[Python]python Study notes (ii)--FAQ

1,python if __name__ = = "__main__": the Role of
Determine whether the current module is directly invoked or directly executed, if the current module is called, then if __name__ = = "__main__": After the statement will not be executed, if the current pattern is executed directly, then if __name__ = = "__main__ ": The following statement will be executed to ~

2,python processing binary data using struct structure body

Python processes binary data using struct structure body

3, the values in the dictionary are unordered, as in the following example:

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1. >>> a = {' agitation ': 3, ' spend ': 2, ' Encro ': 1}
2. >>> for i in A.keys ():
3. ... i
4. ...
5. ' Encro '
6. ' Spend '
7. ' Agitation '

4,python How to create directories and files recursively

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2. def creat_file (finame):
4. TEMPDIR=OS.GETCWD ()
6. Basename=os.path.basename (Finame)
8. Dirname=os.path.dirname (Finame)
10. Os.chdir (dirname)
12. File (basename,' W ')
14. Os.chdir (TempDir)
18. def creat_dir (fname):
20. Filename=fname
22. N=filename.find ('/')
24. if n>0:
26. dir= filename[0:filename.find ('/') +1]
28. Print Dir
30. If not os.path.exists (dir):
32. Os.makedirs (dir,mode=0777)
34. Os.chdir (dir)
36. Dirleft=filename[filename.find ('/') + 1:]
38. Creat_dir (Dirleft)
40. Else:
42. dir= filename[0:filename.find ('/') +1]
44. Dirleft=filename[filename.find ('/') + 1:]
46. Os.chdir (dir)
48. Creat_dir (dirleft) <strong> </strong>

5,python how to invoke a shell script
Os.system (' mkdir SS ')

Os.system () The method of passing variables is as follows,

Log= "Main.log"

Os.system (' cat%s | grep nvram '%log)


6, how to call a regular expression in Python
Python's Re module
The following code means finding a string in a string that starts with uppercase or lowercase letters
Cfilename= ' ABDAA123AA '
M=re.search (' [a-z,/,a-z,_]+ ', cFileName)
Print M.group (0)

7,python How to use all variables

Define the global variables in a separate module:
#gl. py
Gl_1 = ' Hello '
gl_2 = ' World '

Use in other modules
#a. py
Import GL

def Hello_world ()
Print Gl.gl_1, gl.gl_2
For variable sharing between different files

8, cite all the files in the current directory and print

Listfile=os.listdir (OS.GETCWD ())

For line in ListFile:

Print Line

9,python use with and or ~

and and OR keywords ~

10. Parsing command-line arguments using the Getopt module

Examples are as follows:

Parameter args is generally sys.argv[1:]
Shortopts short Format (-)

On the command line, enter:
Python test.py-i 127.0.0.1-p 80 55 66
Python test.py--ip=127.0.0.1--port=80 55 66
The following code:
Try
Options,args = Getopt.getopt (sys.argv[1:], "HP:I:", ["Help", "ip=", "port="])
Except Getopt. Getopterror:
Sys.exit ()
For Name,value in Options:
If name in ("-H", "--help"):
Usage ()
If name in ("-I", "--ip"):
print ' IP is----', value
If name in ("-P", "--port")

print ' port is----', value

[Python]python Study notes (ii)--FAQ