。。。。。
| .
prs22
prs22b
prs42
prs43
prs52
prs53
| . toolDoc2 __init__ dict21 dict22 dict23n -1 dict23n -2 dict23n -3 dict24 .. | ... |
prs43
ReplyDelete$$ Types of Classes in programming
A utility/tools, not saving the external data, or the related data
B utility/tools, saving the external data, or the related data
C functions, serving for the specific external data
D functions, serving the internal data
Module, contains
IMPORT section
class dummy(): pass
p = dummy() # global var
def main():
CLASSES section
class doc2C():
helpT=[0]
lessonT=[0]
i6c=toolDoc2.info6C(self)
main()
$$ Class Oriented
def __init__(self): pass
# main() part, to use classObjName.var; this is more convenience
# in __inti__, have to use self.var; this is more clas-oriented
# def __new__(cls): pass # for inheritance of multi-generation, multi-parent
# def __call__(self): pass # for mainCObj()
# def __init__(self): pass # for post-instantiation of object
$$ Loading Chinese py file
# from prs2ndu8 import *
# prs2ndu8.py saved in utf-8
# succeed, but require : str.decode("utf8")
# add coding: utf-8 ; succeed in IMPORT; no need of decode()
# from prs2ndu import *
# prs2ndu.py saved in Unicode; fail in IMPORT
# from prs2ndub import *
# prs2ndu.py saved in Unicode big endian; fail in IMPORT
# from prs2ndasc import *
# prs2ndasc.py saved in ascii/ANSI endian; fail in IMPORT
# add coding: cp936/gbk ; fail in IMPORT
# add coding: utf-8 ; succeed in IMPORT
$$ List
pop([id]); remove(value);
append(value); extend(list); insert(id, value);
index(value); count(value); reverse(); sort();
del list[:]/all; del [pos:stop]
tuple
a = (1,2), (3,4) >>> a == ((1,2), (3,4))
a = 1, >>> a == (1,)
a,b = (1,2) >>> a==1; b==2
a,b = 1,2 >>> a==1; b==2
(a,b) = (1,2) >>> a==1; b==2
list("abc") >>> ["a","b","c"]
tuple("abc") >>> ("a","b","c")
"""
# END of LESSON text string
helpT[0] = """
$$ import prs32
class parseClauseC():
thisP = p
def __init__():
def intoSentence(self):
def formPhrase(self, tt):
def deleteChinese(self, line):
def initWord(self):
$$ Structure of classes, functions
import toolDoc2, re
# from prs2ndasc import dict6
class dummy(): pass
p = dummy() # var; global passing channel
pw = dummy() # word, suffix, prefix to tell the part of speech
text2 = ""
def main():
def main6():
def main5():
def test():
class transferFile():
def workLines (self, inFile, outFile):
def lineToTuple(self, line):
class fileOpr6():
def openFile(self, fileNameStr):
def closeFile(self):
def initGlobal():
prs53
ReplyDelete$$ Function Closure
def a(): def b(): print x; pass; x = 100; return b; c = a()
# c=a() by return inner_func : closure
# inner var can be accessed by b()
$$ Exception Management
try: do_someting
ecept: do_exception
finally: do_finally
class manager():
def __init__(self): pass
def __enter__(self): pass # or, return AS_attribute
def __exit__(self [, exc_type, exc_value, traceback]):
do_FINALLY
if tracback: do_exception
pass
with manager():
DO_something
@decorator # if deco is a class
# @ will invoke deco.__init__()
# declare __init__(self,func): self.func=func;
# func() is invoked, then instead, deco.__call__() is invoked
# @ :: func=deco.__call__
@decorator # if deco is a function
# def deco(f): def f2(): pass; (f2.__name__=f.__name__;) return f2
# def f2(*args, **kwargs): return f(*args, **kwargs);
# def f2(*args, **kwargs): f(*args, **kwargs);
# @decon :: fucn=deco(func)
__new__(cls)
__init__(self [,args])
__call__(self [, args]) # obj()
__repr__(self) # obj, repr(obj)
__str__(self) # str(obj)
__enter__() # for with statement
__exit__() # for with statement
__del__(self) # del obj
decorator :
add pre- and post- functions, even replace the original
work on only one function
with statement :
exception + decorator (will not replace the original)
work on many statements
try..finally : make things clear; with statment makes clean
try..except : alternative to if..else
$$ Sort
L.sort(cmpFUNC=None, keyFUNC=None, reverse=False)
L = [{1:5,3:4},{1:3,6:3},{1:1,2:4,5:6},{1:9}]
def f2(a,b):
print a[1],b[1] # get the value, {1:5}[1]==5
return a[1]-b[1]
L.sort(cmp=f2)
L.sort() # retrun a new L
L2 = sorted(L)
$$ Class Oriented
def __init__(self): pass
# main() part, to use classObjName.var; this is more convenience
# in __inti__, have to use self.var; this is more clas-oriented
# def __new__(cls): pass # for inheritance of multi-generation, multi-parent
# def __call__(self): pass # for mainCObj()
# def __init__(self): pass # for post-instantiation of object
$$ Loading Chinese py file
# from prs2ndu8 import *
# prs2ndu8.py saved in utf-8
# succeed, but require : str.decode("utf8")
# add coding: utf-8 ; succeed in IMPORT; no need of decode()
# from prs2ndu import *
# prs2ndu.py saved in Unicode; fail in IMPORT
# from prs2ndub import *
# prs2ndu.py saved in Unicode big endian; fail in IMPORT
# from prs2ndasc import *
# prs2ndasc.py saved in ascii/ANSI endian; fail in IMPORT
# add coding: cp936/gbk ; fail in IMPORT
# add coding: utf-8 ; succeed in IMPORT
$$ List
pop([id]); remove(value);
append(value); extend(list); insert(id, value);
index(value); count(value); reverse(); sort();
del list[:]/all; del [pos:stop]
tuple
a = (1,2), (3,4) >>> a == ((1,2), (3,4))
a = 1, >>> a == (1,)
a,b = (1,2) >>> a==1; b==2
a,b = 1,2 >>> a==1; b==2
(a,b) = (1,2) >>> a==1; b==2
list("abc") >>> ["a","b","c"]
tuple("abc") >>> ("a","b","c")
prs22
ReplyDelete$$ Loading Chinese py file
# from prs2ndu8 import *
# prs2ndu8.py saved in utf-8
# succeed, but require : str.decode("utf8")
# add coding: utf-8 ; succeed in IMPORT; no need of decode()
# from prs2ndu import *
# prs2ndu.py saved in Unicode; fail in IMPORT
# from prs2ndub import *
# prs2ndu.py saved in Unicode big endian; fail in IMPORT
# from prs2ndasc import *
# prs2ndasc.py saved in ascii/ANSI endian; fail in IMPORT
# add coding: cp936/gbk ; fail in IMPORT
# add coding: utf-8 ; succeed in IMPORT
$$ List
pop([id]); remove(value);
append(value); extend(list); insert(id, value);
index(value); count(value); reverse(); sort();
del list[:]/all; del [pos:stop]
tuple
a = (1,2), (3,4) >>> a == ((1,2), (3,4))
a = 1, >>> a == (1,)
a,b = (1,2) >>> a==1; b==2
a,b = 1,2 >>> a==1; b==2
(a,b) = (1,2) >>> a==1; b==2
list("abc") >>> ["a","b","c"]
tuple("abc") >>> ("a","b","c")
prs22b -1
ReplyDelete$$ Chome, Python Shell
C:\Documents and Settings\Administrator\Local Settings\Application Data\ \
Google\Chrome\User Data\Default\Extensions\ \
gdiimmpmdoofmahingpgabiikimjgcia\2.2.2_0\extern\ \
python\closured\include\python2.7
python\closured\lib\python2.7\plat-linux2
python\reloop-closured\lib\python2.7\plat-linux2
python\unclosured\lib\python2.7\plat-linux2
sys.path
['', 'lib/python27.zip',
'/lib/python2.7/',
'/lib/python2.7/plat-linux3',
'/lib/python2.7/lib-tk',
'/lib/python2.7/lib-old',
'/lib/python2.7/lib-dynload']
$$ Class Study
SUPERclas = super(THISclassNAME, self)
Find the caller of function ::
import inspect
inspect.stack()[1][3] # this function
inspect.stack()[2][3] # caller function
__new__(cls [, *args, **kwargs])
invoked before instancation
deal with class inheritance;
track of superclasses, override issue
return object.__new__(cls, *args, **kwargs)
for multiple inheritance ::
objList[0].__dict__.update(copy.deepcopy(obj.__dict__))
cls : can be replaced by any id: cls2, typ
__init__(self [, arg1, arg2])
invoked after instancation
deal with class arguments, properties,
initiation
to set initial values to properties,
to run some functions
__call__(self [, arg1, arg2])
invoked when the object/instance is used as a function
$$ String Replacement
STRING.replace(old_sub, new_sub [, max])
re.sub(r"RE", repl, STRING, count=0, flags=0)
# r"" means "\"; or "\\"
# works woth ()(), groups >> \1, \2
# if repl is function, def func(matchobj): matchobj.group(1)
# match.group(0) on "..(..)..", match.group(1) on (..)
# if no () group in REexpr, then use: match.group(0)
re.subn(pattern, repl, string, count=0, flags=0)
# Perform the same operation as sub(),
# but return a tuple (new_string, number_of_subs_made).
REexp.sub(new_sub, string [,count=0])
# count=0, means all
# REexp = re.compile('(new1|new2|new3)')
>>> p = re.compile('x*')
>>> p.sub('-', 'abxd')
'-a-b-d-'
# how come???
>>> p = re.compile('section{ ( [^}]* ) }', re.VERBOSE)
>>> p.sub(r'subsection{\1}','section{First} section{second}')
'subsection{First} subsection{second}'
# () >> \1; groups stay the same as before
>>> p = re.compile('section{ (?P [^}]* ) }', re.VERBOSE)
>>> p.sub(r'subsection{\1}','section{First}')
'subsection{First}'
>>> p.sub(r'subsection{\g<1>}','section{First}')
'subsection{First}'
>>> p.sub(r'subsection{\g}','section{First}')
'subsection{First}'
# (?P..) >> \1, \g<1>, \g
sub("(?i)b+", "x", "bbbb BBBB") returns 'x x'.
# (?!) ignore case
$$ String Translation
* Use of Table module, named "maketrans"
from string import maketrans # Required to call maketrans function.
#
intab = "aeiou"
outtab = "12345"
trantab = maketrans(intab, outtab) # (a-1, e-2, i-3, o-4, u-5)
#
str = "this is string example....wow!!!";
print str.translate(trantab, 'xm');
prs22b -2
ReplyDelete$$ String Search
RES = re.search("c", "abcde")
# containing
Return None if no position in the string matches the pattern;
RES.groups()
RES.gruoup(0)
RES.group('NAME') for r"(?P)"
REpattern.search(string[, pos[, endpos]])
re.match("c", "abcde")
# starting with
LIST = re.split (REepr, STRING [, max])
re.findall(r"RE", STRING)
string.find(s, sub[, start[, end]]) # Return -1 on failure
string.rfind(s, sub[, start[, end]]) # but find the highest index.
string.index(s, sub[, start[, end]])
# but raise ValueError when the substring is not found
string.rindex(s, sub[, start[, end]])
string.count(s, sub[, start[, end]])
a = re.compile(r'''\d + # the integral part
\. # the decimal point
\d * # some fractional digits''', re.X)
b = re.compile(r"\d+\.\d*")
# re.X, re.VERBOSE : Whitespace within the pattern is ignored,
except when in a character class or preceded by an unescaped backslash,
and, when a line contains a '#'
neither in a character class
or preceded by an unescaped backslash,
all characters from the leftmost such '#'
through the end of the line are ignored.
$$ Chinese Code
# -*- coding: utf-8 -*-
utf-8, big5, gbk, gb2312, cp936
* decode
text_gb2312.decode("gbk") # unncessary if system is in GB
text_big5.decode("big5")
text_utf.decode("utf9")
str_gb2312.decode("gb2312").encode("utf-8")
# TRADITIONAL : big5, big5hkscs, cp950
# UNIFIED : gbk, gb18030,
# SIMPLIFIED : gb2312, hz
# JKC : iso2022_jp_2,
# UNICODE : utf_7, utf_8, utf_16, utf_32;
# UNICODE : utf_16_be, utf_16_le, utf_32_be, utf_32_le,
* Windows system, set to Chinese - China; GB
line.decode("gbk")
10_28_Sermon_gb2312.txt
10_28_Sermon_big5.txt
10_28_Sermon_utf8.txt
10_28_Sermon_utf16.txt
This comment has been removed by the author.
ReplyDeleteprs22b -3
ReplyDelete$$ File Arrangment
documentation
requires : toolDoc, p.helpT, p.lessonT [txt,hdg,pos]
help2() : structure of project, files, classes, functions
lesson2() : learning, language, built-in, features, tips
each module
invokes module toolDoc
for documentation, to make help2(), lesson2()
contains
var : p (a dummy object),
func : main(), help2(), lesson2(), initGlobal()
each sub-module
contains classes only,
besides: main(), help2(), lesson2()
class CLASS():
def __init__(self, CALLERp):
self.thisP = p;
self.callerP = CALLERp
# exec "self.callerP."+"FUNC()"
# callerP: p.CLASSo.thisP.FUNC()
file naming
AAA999BB88 :
AAA : project name
999 : version serial, 2..8, excep 0/1/9
9 extention, (1) 2..8, 922..988; (2) 2..8, 92..98;
0 help/document;
1/0 level separator, 2.3=213, or 203
BB : sub-modules, b..w, except l/j/x/u/n/vowels
x extention, b..w, xbb..xww
j level separator, BjB, xbbxcc=bbjcc, or bb.cc
u tool/utility, more common to other projects
n notes, or nSUBname
a/e/i/o/u//l/j (reserved)
B sub-module, b..w, xbb..xww
BB sub-sub-module, bc..bw, BB* bxcc..bxww
BBB sub-sub-sub-module, BBB* bcd..bcw, bcxdd..bcxww
B*B, xbbc..xbbw, B*B* xbbxcc..xbbxww
99 : (reserved), temp for revisions, copies
prs42
ReplyDelete$$ Loading Chinese py file
# from prs2ndu8 import *
# prs2ndu8.py saved in utf-8
# succeed, but require : str.decode("utf8")
# add coding: utf-8 ; succeed in IMPORT; no need of decode()
# from prs2ndu import *
# prs2ndu.py saved in Unicode; fail in IMPORT
# from prs2ndub import *
# prs2ndu.py saved in Unicode big endian; fail in IMPORT
# from prs2ndasc import *
# prs2ndasc.py saved in ascii/ANSI endian; fail in IMPORT
# add coding: cp936/gbk ; fail in IMPORT
# add coding: utf-8 ; succeed in IMPORT
$$ List
pop([id]); remove(value);
append(value); extend(list); insert(id, value);
index(value); count(value); reverse(); sort();
del list[:]/all; del [pos:stop]
tuple
a = (1,2), (3,4) >>> a == ((1,2), (3,4))
a = 1, >>> a == (1,)
a,b = (1,2) >>> a==1; b==2
a,b = 1,2 >>> a==1; b==2
(a,b) = (1,2) >>> a==1; b==2
list("abc") >>> ["a","b","c"]
tuple("abc") >>> ("a","b","c")
prs52
ReplyDelete$$ Class Oriented
def __init__(self): pass
# main() part, to use classObjName.var; this is more convenience
# in __inti__, have to use self.var; this is more clas-oriented
# def __new__(cls): pass # for inheritance of multi-generation, multi-parent
# def __call__(self): pass # for mainCObj()
# def __init__(self): pass # for post-instantiation of object
$$ Loading Chinese py file
# from prs2ndu8 import *
# prs2ndu8.py saved in utf-8
# succeed, but require : str.decode("utf8")
# add coding: utf-8 ; succeed in IMPORT; no need of decode()
# from prs2ndu import *
# prs2ndu.py saved in Unicode; fail in IMPORT
# from prs2ndub import *
# prs2ndu.py saved in Unicode big endian; fail in IMPORT
# from prs2ndasc import *
# prs2ndasc.py saved in ascii/ANSI endian; fail in IMPORT
# add coding: cp936/gbk ; fail in IMPORT
# add coding: utf-8 ; succeed in IMPORT
$$ List
pop([id]); remove(value);
append(value); extend(list); insert(id, value);
index(value); count(value); reverse(); sort();
del list[:]/all; del [pos:stop]
tuple
a = (1,2), (3,4) >>> a == ((1,2), (3,4))
a = 1, >>> a == (1,)
a,b = (1,2) >>> a==1; b==2
a,b = 1,2 >>> a==1; b==2
(a,b) = (1,2) >>> a==1; b==2
list("abc") >>> ["a","b","c"]
tuple("abc") >>> ("a","b","c")
"""
# END of LESSON text string
toolDoc2
ReplyDelete$$ File arrangement
Each module contains:
class dummy(): pass
p = dummy()
def main()
def initGlobal() # prepare the dummy "p"
p.i6c = toolDoc2.info6C(p) # give the reference "p"
p.helpT=[""] # structure of files/modules, classes, functions,
p.lessonT=[""] # learning of language, built-in,
Mainly, "p" handles all global var, including external var
* Related variables and functions are grouped
into a class or module, as properties and methods
* var inside func is local, temporary until func is done
* var inside class is static, active until object is deleted
* var inside a module/file is static, no other modules can access
unless from MOD import *
unless invoke by SUBmodule.var
* Only the object var (as reference) is able to cross the scopes
__init__
ReplyDelete$$ Notes - arguments
func (farg, *args)
func (1, 2, 3) == farg=1, args=[2,3]
func (farg, **kwargs)
func (f=1, a1=2, a2=3) == farg=1, kwarg={"a1":2,"a2"=3}
# in RE module, result.start(i) == result.group(i+1).posINoriginal
# y[yy.start():yy.end()]==yy for yy in re.find(REepr, y, FLAGS)
# yy.start() == yy.start(0) for yy.group(1)
# find all headings; re.M a flag of multi-line
dict21
ReplyDelete$$ Chinese internal code
# -*- coding: utf-8 -*-
# cp936, gb2312 (, GBK、GB18030), utf8, utf16, big5
# LIST = STRING.split (SEPARATOR, MAXsplits)
# re.split (REexp, STRING)
# LIST = re.split ("sep|sep", STRING)
# SEPARATOR.join (SEQUENCE)
# Big-5 ok:
# if line = FILE.readline()
# if "".join(line.split(","))
# if "".join(line.split(",")[2])
# ecd_21b_tw2.csv : unicode(line, "big5")
# line.split()[2].decode("big5") = u"xxx"
# unicode(line, "big5") = u"xxx"
# line.decode("big5") = u"xxx"
# line.index (SUBstringCHINESE)
$$ Functions to use files.
f.open ("path/filename","type")
The first argument is a string containing the filename.
The second argument is another string containing a few characters
describing the way in which the file will be used.
mode can be 'r' when the file will only be read,
'w' for only writing (an existing file with the same name will be erased),
and 'a' opens the file for appending;
any data written to the file is automatically added to the end.
'r+' opens the file for both reading and writing. The mode argument is optional;
'r' will be assumed if it’s omitted.
On Windows, 'b' appended to the mode opens the file in binary mode,
so there are also modes like 'rb', 'wb', and 'r+b'.
f.read()
# 'This is the entire file.\n'
f.readline()
# read one line at a time;
# then 'Second line of the file\n'
f.readlines (intByte)
the same as read(), but parse into lines;
If given an optional parameter intByte, it reads that many bytes from the file and enough more to complete a line,
f.xreadlines()
# the same as readlines() to read the entire file,
# readlines() returns a list, xreadlines returns a iterator
for line in f
the best way to read a line;
range() returns an iterator object;
iterator, a generator-like tuple, one same space for all elements, next() required
dict22
ReplyDelete$$ Import Module
import MOD2 [as M1], MOD3 [as M2]
from MOD import IDENTIFIER [as ID2], IDEN [as ID3]
from MOD import (IDENTIFIER [as ID2], IDEN [as ID3])
from [PAK.]PACKAGE import MOD
from MOD import * # import all identifiers
import sys
del sys.modules ["MYmodule"] # no way, Python does not support
del MYmodule
reload (MYmodule)
imp.reload (MYmodule) # in Python 3
setattr(package, "MYmodule", None)
$$ Chinese internal code
# -*- coding: utf-8 -*-
# cp936, gb2312 (, GBK、GB18030), utf8, utf16, big5
# LIST = STRING.split (SEPARATOR, MAXsplits)
# re.split (REexp, STRING)
# LIST = re.split ("sep|sep", STRING)
# SEPARATOR.join (SEQUENCE)
# Big-5 ok:
# if line = FILE.readline()
# if "".join(line.split(","))
# if "".join(line.split(",")[2])
# ecd_21b_tw2.csv : unicode(line, "big5")
# line.split()[2].decode("big5") = u"xxx"
# unicode(line, "big5") = u"xxx"
# line.decode("big5") = u"xxx"
# line.index (SUBstringCHINESE)
$$ Functions to use files.
f.open ("path/filename","type")
The first argument is a string containing the filename.
The second argument is another string containing a few characters
describing the way in which the file will be used.
mode can be 'r' when the file will only be read,
'w' for only writing (an existing file with the same name will be erased),
and 'a' opens the file for appending;
any data written to the file is automatically added to the end.
'r+' opens the file for both reading and writing. The mode argument is optional;
'r' will be assumed if it’s omitted.
On Windows, 'b' appended to the mode opens the file in binary mode,
so there are also modes like 'rb', 'wb', and 'r+b'.
f.read()
# 'This is the entire file.\n'
f.readline()
# read one line at a time;
# then 'Second line of the file\n'
f.readlines (intByte)
the same as read(), but parse into lines;
If given an optional parameter intByte, it reads that many bytes from the file and enough more to complete a line,
f.xreadlines()
# the same as readlines() to read the entire file,
# readlines() returns a list, xreadlines returns a iterator
for line in f
the best way to read a line;
range() returns an iterator object;
iterator, a generator-like tuple, one same space for all elements, next() required
dict23n -1
ReplyDelete$$ Exception Handling
try:
operation_that_can_throw_ioerror()
except IOError:
handle_the_exception_somehow()
else:
# we don't want to catch the IOError if it's raised
another_operation_that_can_throw_ioerror()
finally:
something_we_always_need_to_do()
try:
You do your operations here;
except ExceptionI:
If there is ExceptionI, then execute this block.
except ExceptionII:
If there is ExceptionII, then execute this block.
else:
If there is no exception then execute this block.
try:
You do your operations here;
except:
If there is any exception, then execute this block.
try:
You do your operations here;
except Exception1, Exception2:
If there is any from the exception list, then execute this block.
try:
You do your operations here;
finally:
This would always be executed,
whether the try-block raised an exception or not.
except ValueError, Argument_detail:
print "The argument does not contain numbers\n", Argument_detail
except (RuntimeError, TypeError, NameError):
except IOError, (errno, strerror):
print "I/O error(%s): %s" % (errno, strerror)
# raise [Exception [, args [, traceback]]]
try:
Business Logic here...
if level < 1:
raise "Invalid level!", level
except "Invalid level!":
Exception handling here...
>>> try:
... raise Exception('spam', 'eggs')
... except Exception, inst:
... print type(inst) # the exception instance
... print inst.args # ('spam', 'eggs'), arguments stored in .args
... print inst # ('spam', 'eggs'), __str__ allows args to
# printed directly
... x, y = inst # __getitem__ allows args
# to be unpacked directly
$$ Print statement
# Formatting
print string.rjust(`x*x*x`, 4)
print '%2d %3d %4d' % (x, x*x, x*x*x)
string.zfill('12', 5)
print "".join(list2)
print('h', end='') # Python 3
print('a', 'b', 'c', sep='') # Python 3
print repr(x).rjust(2)
print '%-10s ==> %10d' % (name, phone)
# %-10s spaces at left
table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 7678}
print '%(Jack)d; %(Sjoerd)d; %(Dcab)d' % table
# works with dictionary
class WritableObject:
def __init__(self):
self.content = []
def write(self, string):
self.content.append(string)
# example with redirection of sys.stdout
foo = WritableObject() # a writable object
sys.stdout = foo # redirection
print "one, two, three, four" # some writing
print "little hat"
print "little hat"
sys.stdout = sys.__stdout__ # remember to reset sys.stdout!
print "foo's content:", foo.content # show the result of the writing
# example with redirection of the print statement
bar = WritableObject() # another writable object
print >>bar, "one, two, three, four" # some (redirected) writing
print >>bar, "little hat made of paper"
print "bar's content:", bar.content # the result
dict23n -2
ReplyDelete$$ SQL SQLite3
import sqlite3
>>> sqlite3.version # the version of the pysqlite
>>> sqlite3.sqlite_version # the version of the SQLite database library
sqlite> .tables # a list of tables in the test.db database
sqlite> .exit # terminates the interactive session of the sqlite3 command line tool.
data3 = str(input('Please enter name: '))
query = "DELETE FROM Zoznam WHERE Name = '%s';" % data3.strip()
mydata = c.execute(query)
# Open a database
conn = sqlite3.connect('dict.db') # open a database
conn = sqlite3.connect(':memory:')
# Create a table
CREATE TABLE tab2 (col3 TEXT, col4 INT, col5 TEXT)
CREATE TABLE Friends(Id INTEGER PRIMARY KEY, Name TEXT);
CREATE TABLE Images(Id INTEGER PRIMARY KEY, Data BLOB);
# Insert a record
INSERT INTO Cars VALUES (1,'Audi',52642)
INSERT INTO Cars (Price) VALUES (52642)
# Update a record
UPDATE tab2 SET col3 = 'John Doe' WHERE col3 = 'Andy Hunter'
# Delete a record
DELETE FROM tab2 WHERE col3 = 'John Doe'
# Delete a table
DROP TABLE IF EXISTS tab1
sql = "SELECT * FROM albums WHERE artist=?"
c.execute(sql, [("Red")])
# c.execute("SELECT * FROM albums WHERE artist=?", [("Red")])
c.fetchall()
c.fetchone()
while True:
row = c.fetchone()
if row == None: break
print row[0], row[1], row[2]
with con:
con.row_factory = lite.Row
# list into dictionary with field names as keys
...
rows = cur.fetchall()
for row in rows:
print "%s %s %s" % (row["COL2"], row["COL3"], row["COL4"])
for row in cursor.execute("SELECT rowid, * FROM albums ORDER BY artist"):
print row
conn.row_factory = sqlite3.Row
# Row objects that are kind of like Python dictionaries
# and give you access to the row’s fields just like a dictionary.
# Insert image
fin = open("woman.jpg", "rb")
img = fin.read()
data = img
binary = sqlite3.Binary(data)
cur.execute("INSERT INTO Images(Data) VALUES (?)", (binary,) )
# Read image
cur.execute("SELECT Data FROM Images LIMIT 1")
data = cur.fetchone()[0]
fout = open('woman2.jpg','wb')
fout.write(data)
# Metadate
cur.execute('PRAGMA table_info(Cars)')
data = cur.fetchall()
for d in data:
print d[0], d[1], d[2]
=== 0 Id INT
cur.execute('SELECT * FROM Cars')
col_names = [cn[0] for cn in cur.description]
cur.execute("SELECT name FROM sqlite_master WHERE type='table'")
rows = cur.fetchall()
for row in rows:
print row[0]
# execute()
c.execute('SELECT * FROM engchi')
c.execute("SELECT * FROM albums WHERE artist=?", [("Red")])
# works wuith "?" and second arg (list of tuples)
c.execute("UPDATE Cars SET Price=? WHERE Id=?", (uPrice, uId))
cur.execute("SELECT Name, Price FROM Cars WHERE Id=:Id", {"Id": uId})
# :KEY -- dictionry {"KEY": uValue}
c.executescript('SELECT * FROM engchi;')
# executescript issues COMMIT
# commands end with ";"
c.executemany (INSERT INTO engchi (type, word) VALUES (?,?)', ss0s)
# if ssOs = [(1,1), (2,2), (3,3)]
dict23n -3
ReplyDelete$$ Import Module
import MOD2 [as M1], MOD3 [as M2]
from MOD import IDENTIFIER [as ID2], IDEN [as ID3]
from MOD import (IDENTIFIER [as ID2], IDEN [as ID3])
from [PAK.]PACKAGE import MOD
from MOD import * # import all identifiers
import sys
del sys.modules ["MYmodule"] # no way, Python does not support
del MYmodule
reload (MYmodule)
imp.reload (MYmodule) # in Python 3
setattr(package, "MYmodule", None)
$$ Chinese internal code
# -*- coding: utf-8 -*-
# -*- coding: utf-8 -*-
# cp936, gb2312 (, GBK、GB18030), utf8, utf16, big5
# LIST = STRING.split (SEPARATOR, MAXsplits)
# re.split (REexp, STRING)
# LIST = re.split ("sep|sep", STRING)
# SEPARATOR.join (SEQUENCE)
# Big-5 ok:
# if line = FILE.readline()
# if "".join(line.split(","))
# if "".join(line.split(",")[2])
# ecd_21b_tw2.csv : unicode(line, "big5")
# line.split()[2].decode("big5") = u"xxx"
# unicode(line, "big5") = u"xxx"
# line.decode("big5") = u"xxx"
# line.index (SUBstringCHINESE)
$$ Functions to use files.
f.open ("path/filename","type")
The first argument is a string containing the filename.
The second argument is another string containing a few characters
describing the way in which the file will be used.
mode can be 'r' when the file will only be read,
'w' for only writing (an existing file with the same name will be erased),
and 'a' opens the file for appending;
any data written to the file is automatically added to the end.
'r+' opens the file for both reading and writing. The mode argument is optional;
'r' will be assumed if it’s omitted.
On Windows, 'b' appended to the mode opens the file in binary mode,
so there are also modes like 'rb', 'wb', and 'r+b'.
f.read()
# 'This is the entire file.\n'
f.readline()
# read one line at a time;
# then 'Second line of the file\n'
f.readlines (intByte)
the same as read(), but parse into lines;
If given an optional parameter intByte, it reads that many bytes from the file and enough more to complete a line,
f.xreadlines()
# the same as readlines() to read the entire file,
# readlines() returns a list, xreadlines returns a iterator
for line in f
the best way to read a line;
range() returns an iterator object;
iterator, a generator-like tuple, one same space for all elements, next() required
dict24
ReplyDelete$$ Chinese Inner Code
ll = line.decode("gbk")
# decode into u"xxxx"
# Windows system is set for Chinese-China
# py file is set to coding CP936 - GBK
p.rows[30][1].index("bac")
p.rows[30][2].index("院長".decode("gbk"))
mg22
ReplyDeletex=[]; temp2=[x.extend(list(db2[y][3:9])) for y in range(len(db2))]
[db2[x][y] for x in range(len(db2)) for y in range(3,9) ]
# two ways, To get all numbers into one-level list
x=[db2[y][3] for y into range(len(db2))]
# To get all 3rd numbers in one-level list
for x,y,z in ((1,2,3),(4,5,6)): print x,y,z
for x,(y,z) in [(1,(2,3)),(4,(5,6))]: print x,y,z;
# multiple variables in FOR statement
print "%6.4f" % (1.0*st.count(st[0])/len(st))
# calculate the percentage of a number
map(lambda x: 1.0*st.count(x)/len(st), [db2[0][y] for y in range(3,9)])
# list of percentage for a row of numbers
iter(SEQUENCE)
# sequence: list, tuple, string;
# generate an iterator object, (S[0], S[1], ...)
enumerate(LIST)
# generate an iterator object, ((0, L[0]), (1, L[1]), ...)
ITERABLES, must work with IT.next() to get next element;
if sequence changed before next(), then iter() changed as well;
mg23 -1
ReplyDelete$$ A. List Comprehesion
x=[]; temp2=[x.extend(list(db2[y][3:9])) for y in range(len(db2))]
[db2[x][y] for x in range(len(db2)) for y in range(3,9) ]
# two ways, To get all numbers into one-level list
x=[db2[y][3] for y into range(len(db2))]
# To get all 3rd numbers in one-level list
for x,y,z in ((1,2,3),(4,5,6)): print x,y,z
for x,(y,z) in [(1,(2,3)),(4,(5,6))]: print x,y,z;
# multiple variables in FOR statement
print "%6.4f" % (1.0*st.count(st[0])/len(st))
# calculate the percentage of a number
map(lambda x: 1.0*st.count(x)/len(st), [db2[0][y] for y in range(3,9)])
# list of percentage for a row of numbers
$$ B. Iteraables
iter(SEQUENCE)
# sequence: list, tuple, string;
# generate an iterator object, (S[0], S[1], ...)
enumerate(LIST)
# generate an iterator object, ((0, L[0]), (1, L[1]), ...)
ITERABLES, must work with IT.next() to get next element;
if sequence changed before next(), then iter() changed as well;
reduce(f(x,y), [1, 2, 3, 4]) # f(f(f(1,2),3),4)
reduce(f(x,y), [1, 2, 3, 4], 9) # f(f(f(f(9,1),2),3),4)
map(f(x), [1, 2, 3, 4, 5]) # [f(1), f(2), f(3)]; map(func,iterable)
zip("1,2,3"，”a", "b") # ("1a", "2b"); zip(iterable, ...)
mg23 -2
ReplyDelete$$ C. String Formatting
str(OBJ/NUM/STRING/SEQUENCE) # return a string
repr(x) # return a string for interpretation
# replaced into repr MODULE
# Python3 rename to reprlib MODULE
STRING.rjust()
STRING.center()
STRING.ljust()
STRING.zfill(NUM) # fill zero
STRING.format(value1, value2,...) # work with {}
'The value of PI is approximately {}.'.format(math.pi)
'{0} and {1}'.format('spam', 'eggs') # with ordered values
'This {food} is {adjective}.'.format(\
food='spam', adjective='absolutely horrible') # with named values
'The story of {0}, {1}, and {other}.'.\
format('Bill', 'Manfred', other='Georg') # with mixed
'PI is {!r}.'.format(math.pi) # apply repr()
'PI is {!s}.'.format(math.pi) # apply str()
'PI is {0:.3f}.'.format(math.pi) # convert to float with 3 decimals
'PI is {0:10d}.'.format(math.pi) # convert to integer with 10 digits long
table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 8637678}
print ('Jack: {0[Jack]:d}; Sjoerd: \
{0[Sjoerd]:d}; Dcab: {0[Dcab]:d}'.format(table)) # with DICTIONARY
coord = (3, 5)
print 'X: {0[0]}; Y: {0[1]}'.format(coord) # with LIST
'{:<30}'.format('left aligned') # with length of 30 characters
'{:>30}'.format('right aligned')
'{:^30}'.format('centered')
'{:*^30}'.format('centered') # use '*' as a fill char
'{:+f}; {:+f}'.format(3.14, -3.14) # show PLUS and MINUS
'{: f}; {: f}'.format(3.14, -3.14) # show a space for positive numbers
'{:-f}; {:-f}'.format(3.14, -3.14) # show only the MINUS -- same as '{:f}; {:f}'
>>> '{:,}'.format(1234567890) # add thousand separator
>>> 'Correct answers: {:.2%}'.format(19.5/22) # percentage
>>> import datetime
>>> d = datetime.datetime(2010, 7, 4, 12, 15, 58)
>>> '{:%Y-%m-%d %H:%M:%S}'.format(d) # with date MODULE
for align, text in zip('<^>', ['left', 'center', 'right']):\
'{0:{fillx}{alignx}16}'.format(text, fillx=align, alignx=align) # nested
>>> octets = [192, 168, 0, 1]
>>> '{:02X}{:02X}{:02X}{:02X}'.format(*octets) # convert to octets
'C0A80001'
>>> from string import Template
>>> s = Template('$who likes $what')
>>> s.substitute(who='tim', what='kung pao')
'tim likes kung pao'
mg23 -3
ReplyDelete$$ E. Input and Output
s = raw_input('--> ')
print s
>>> f.write('This is a test\n')
>>> f.read() # read the whole file
>>> f.readline() # read one line
>>> f.readlines() # read the whole file, and split into lines
['This is the first line of the file.\n', 'Second line of the file\n']
>>> f = open('/tmp/workfile', 'w')
>>> print f
$$ F. File Functions
FILE.open (FILEname, FILEtype)
# file name can include PATH
# file type: "w", "r", "a"/append, "+r"/both
FILE.close()
FILE.name # file name
FILE.fileno # integer file id in OS
FILE.next() # next line
FILE.tell () # current position, in byte order
FILE.seek (OFFset, /FROM/) # from: 0/begin of file, 1/current, 0/eof of file
FILE.read (/NUMbytes/)
FILE.readline (/NUMbytes/)
FILE.readlines (/NUMbytes/)
FILE.write （STRING)
FILE.writelines (SEQUENCE)
$$ G. String Functions
STRING.strip(/'CHARstringTOdelet'/)
# delete chars from beginning and ending until non desired
# deafult is to delete whitespace
STRING.lstrip(/'CHARstringTOdelet'/) # delete from beginning
STRING.rstrip(/'CHARstringTOdelet'/) # delete from ending
STRING.split (/DELIMETERstring/,/ISaddLINEfeed/) # return a list
STRING.splitlines (/ISappendLINEfeed/)
STIRNGconnector.join (SEQUENCE)
from string import maketrans
intab = "aeiou"
outtab = "12345"
trantab = maketrans(intab, outtab) # a>>1, e>>2,...
str = "this is string example....wow!!!";
print str.translate(trantab, /CHARstringTOdelete/);
mg23 -4
ReplyDelete$$ H. Regular Expression
>>> import re
>>> m = re.search('(?<=abc)def', 'abcdef') # (?<=xx)yy if yy preceded by xx
>>> m.group(0)
'def'
>>> m = re.search('(?<=-)\w+', 'spam-egg')
>>> m.group(0)
'egg'
prog = re.compile(pattern) # compile to re object
result = prog.match(string)
result = re.match(pattern, string)
re.I, re.IGNORECASE; re.M, re.MULTILINE;
re.compile(pattern, flags=0)
re.search(pattern, string, flags=0)
re.match(pattern, string, flags=0)
re.split(pattern, string, maxsplit=0, flags=0)
str=re.sub(pattern, repl, string, count=0, flags=0) # replace
tuple=re.subn(pattern, repl, string, count=0, flags=0) # (str3, numREPL)
>>> re.split('\W+', 'Words, words, words.')
['Words', 'words', 'words', '']
>>> re.split('(\W+)', 'Words, words, words.')
['Words', ', ', 'words', ', ', 'words', '.', '']
>>> re.split('\W+', 'Words, words, words.', 1)
['Words', 'words, words.']
>>> re.split('[a-f]+', '0a3B9', flags=re.IGNORECASE)
['0', '3', '9']
search(string[, pos[, endpos]])
match(string[, pos[, endpos]])
split(string, maxsplit=0)
findall(string[, pos[, endpos]])
finditer(string[, pos[, endpos]])
sub(repl, string, count=0)
subn(repl, string, count=0)
>>> m = re.match(r"(\w+) (\w+)", "Isaac Newton, physicist")
>>> m.group(0) # The entire match
'Isaac Newton'
>>> m.group(1) # The first parenthesized subgroup.
'Isaac'
>>> m.group(2) # The second parenthesized subgroup.
'Newton'
>>> m.group(1, 2) # Multiple arguments give us a tuple.
('Isaac', 'Newton')
>>> m = re.match(r"(?P\w+) (?P\w+)", "Malcolm Reynolds")
>>> m.group('first_name')
'Malcolm'
>>> m.group('last_name')
'Reynolds'
>>> m.group(1)
'Malcolm'
>>> m.group(2)
'Reynolds'
>>> m = re.match(r"(..)+", "a1b2c3") # Matches 3 times.
>>> m.group(1) # Returns only the last match.
'c3'
>>> m = re.match(r"(\d+)\.(\d+)", "24.1632")
>>> m.groups()
('24', '1632')
$$ J. Regular Expression in JavaScript
* Javascript
# \.X \b boudary, \B non boundary;
# \w [A-Za-z0-9_], \W non letter; \d digit [0-9], \D non digit;
# \s whitespace, \S non whitespace;
# \. ., \" ", \$, \^;
# \n line feed, \r c return; \t h-tab, \v v-tab; \f form feed;
# \cX eg. \cM control-M; \0 NULL;
# \.xHH, \uHHHH hex code;
pos ^ beginning, ^a; $ ending, z$
num a* 0 or more 'a's; a+ 1 or more 'a's; a? 0 or 1 'a';
. one of any digit or char
(xx) match xx and store to groups
(?=x) match but not store
x(?=y) match aslo if followed by y
x(?!y) match also if not followed by y
x|y x or y
{n} a{2} 2 a's, aa; a{1,3} a, aa, aaa;
[x] [xyz] x or y or z; [^xyz] no x or y or z; [abcd] == [a-d]
[\b] backspace
exec() re=/d(b)/g; list=re.exec(str);; list=/d(b)/g.exec(str);
# list, list.index, list.input, list[0] /macthed substr
# list[1], list[2]... stored 1, 2...
# re.lastIndex, re.source /re string;
# re.ignoreCase, re.global / all-repeat, re.multiline;
test() re.test(subSTR)
match() list=str.match(regEXP);
search() int=str.search(regEXP);
replace() str3=str2.replace(/(\w+)\s(\w+)/, "$2, $1") # with (xx)'s
# str3=str2.replace(substr,newsub, flgs)
split() list=str.split(separator, /numlist/)
mg24
ReplyDelete# __repr__ returns a string to execute
# __str__ works in PRINT statement
# inside class, only methods, def func(self, [args])
# inside method, call by self.property and self.method
mg25
ReplyDeletemk1-p, sk2-p; mt3-p; sk1-p, sk3-p, st1-p, st3-p
EXEC statement, exec COMMANDstring may return a value
EVAL function, eval (EXPRESSIONstring) must return a value
COMPILE function, compile (COMMANDstring, "", EXECfunc)
compile(source, filename, mode[, flags[, dont_inherit]])
EXPR function,
returns a COMMANDstring for eval(expr(object))
works with __repr__ in class
# exec STATEMENTstring
# eval EXPstring
# map (FUNC, ARG2list, ARG3list)
# __repr__ returns a string to execute
# __str__ works in PRINT statement
# inside class, only methods, def func(self, [args])
# inside method, call by self.property and self.method
a += b - c :: a = a + (b - c)
[x /if switch(x) else xx/ for x in items /if filter(x)/]
mg24h
ReplyDelete$$ List of Methods : All
import toolDoc
CLASS dummy()
p = dummy() # global var
DEF main()
DEF help2() # this function
DEF lesson2() # learned during coding
DEF initGlobal()
$$ Tip : Global variable through dummy class
class dummy():
# PURPOSE : to create an object to carry values among classes or functions
# REASON : in class/function, cannot reach global simple variables (number, string)
# USAGE : x=dummy(); x.a=2; del x.a; # add/remove a properties
pass
p = dummy()
# global passing channel