1.1 Python OS. Path Module
OS. Path. abspath (PATH) # returns the absolute path.
OS. Path. basename (PATH) # returns the file name OS. Path. commonprefix (list) # returns the longest path of all paths in List (multiple paths. OS. path. dirname (PATH) # returns the file path OS. path. exists (PATH) # True is returned if the path exists, and falseos is returned if the path is damaged. path. lexists # If the path exists, true is returned. If the path is damaged, trueos is returned. path. expanduser (PATH) # Put "~ "And "~ Convert user to user directory OS. path. expandvars (PATH) # Replace the "$ name" and "$ {name}" OS in the path based on the value of the environment variable. path. getatime (PATH) # returns the last time the path was entered. OS. Path. getmtime (PATH) # returns the last modification time under this path. OS. path. getctime (PATH) # returns the size of the path OS. path. getsize (PATH) # returns the file size. If the file does not exist, the system returns the error OS. path. isabs (PATH) # determine whether it is an absolute path OS. path. isfile (PATH) # determine whether the path is a file OS. path. isdir (PATH) # determine whether the path is a directory OS. path. islink (PATH) # determine whether the path is linked to the OS. path. ismount (PATH) # determine whether the path is a mount point () OS. path. join (path1 [, path2 [,...]) # combine the Directory and file name into a path OS. path. normcase (PATH) # convert the case and slash OS of the path. path. normpath (PATH) # standard path string form OS. path. realpath (PATH) # returns the real path OS of path. path. relpath (path [, start]) # Calculate the relative path OS from start. path. samefile (path1, path2) # determine whether the directory or file is the same as OS. path. sameopenfile (FP1, fp2) # determine whether FP1 and fp2 point to the same file OS. path. samestat (STAT1, stat2) # determine whether stat tuple STAT1 and stat2 point to the same file OS. path. split (PATH) # divide the path into dirname and basename, and return an OS. path. splitdrive (PATH) # It is generally used in windows and returns the OS, which consists of the drive name and path. path. splitext (PATH) # split the path, and the OS with the path name and file extension is returned. path. splitunc (PATH) # splits the path into a load point and a file OS. path. walk (path, visit, ARG) # traverse the path and call the visit function in each directory. The visit function must have three parameters (ARG, dirname, names ), dirname indicates the Directory Name of the current directory, names indicates all file names in the current directory, and ARGs indicates the third parameter OS of the walk. path. supports_unicode_filenames # Sets whether Unicode path names are supported
1.2 Python OS. listdir
In Python OS. in listdir, we can list the specific operation solutions of all related files and directories in Dir, and how to use the OS in Python. path. the isfile () function is used to determine whether the relevant path is a file. The following is a detailed description of the article.
Python determines whether a file is used in the python OS. listdir function to determine whether a path is a file. The function prototype is as follows.
- os.path.isfile(path)
The parameter meanings are as follows. Path: The Path to be determined. The following example checks whether E: \ book \ Temp is a file.
- >>> import os
- >>> os.path.isfile('E:\\book\\temp')
Determine whether it is a file
- False
E: \ book \ Temp is not used to list all files in the directory.
Keywords:
- dirimport string, os, sys
- dir = '/var'
- print '----------- no sub dir'
- files = os.listdir(dir)
- for f in files:
- print dir + os.sep + f
- print '----------- all dir'
- for root, dirs, files in os.walk(dir):
- for name in files:
- print os.path.join(root, name)
The preceding Python OS. listdir can list all files and directories in Dir, but does not include contents in subdirectories. OS. Walk can traverse all the following directories, including subdirectories.
1.3 string processing
Judgement-A bool value is usually returned. |
Str. isalpha () |
Whether to include only text |
Str. isdecimal () |
Whether to include only numbers (multilingual numbers) |
Str. isdigit () |
Whether to include only numbers (0 ~ 9) |
Str. isnumeric () |
Whether to contain only numeric characters |
Str. isalnum () |
Whether it only contains text and numbers |
Str. isidentifier () |
Is it a legal identifier? |
Str. islower () |
Lowercase? |
Str. isupper () |
Are all uppercase letters? |
Str. istitle () |
Whether the first letter of each word is capitalized |
Str. isprintable () |
Whether to include only printable characters |
Str. isspace () |
Whether to contain only white space characters |
Str. startswith (prefix [, Start [, end]) |
Prefix or not |
Str. endswith (suffix [, Start [, end]) |
End with suffix? |
Modifier-a modified string is usually returned. |
Str. capitalize () |
Returns an uppercase string. |
Str. Title () |
Returns an uppercase string of each word. |
Str. expandtabs ([tabsize]) |
"\ T" to convert to Space |
Str. Upper () |
Full conversion to uppercase |
Str. Lower () |
Convert all to lowercase letters |
Str. Ljust (width [, Fillchar]) |
Align left and fill right |
Str. Must ust (width [, Fillchar]) |
Right alignment, left Filling |
Str. Center (width [, Fillchar]) |
Center, filled on both sides |
Str. lstrip ([chars]) |
Remove left white space or custom characters |
Str. rstrip ([chars]) |
Remove right white space or custom characters |
Str. Strip ([chars]) |
Remove white spaces or custom characters on both sides |
Str. swapcase () |
Case sensitivity |
Str. zfill (width) |
Fill the left side with 0 to the specified width, which is generally used to modify numbers |
Search & replace |
Str. Count (sub [, Start [, end]) |
Calculate the number of sub occurrences between [start, end) |
Str. Find (sub [, start [, end]) |
|
Str. Index (sub [, start [, end]) |
|
Str. rfind (sub [, start [, end]) |
|
Str. rindex (sub [, start [, end]) |
|
Str. Replace (old, new [, Count]) |
|
Splitting & Combination |
Str. Join (iterable) |
|
Str. Partition (SEP) |
|
Str. rpartition (SEP) |
|
Str. Split ([Sep [, maxsplit]) |
|
Str. rsplit ([Sep [, maxsplit]) |
|
Str. splitlines ([keepends]) |
|
Conversion |
Hex (X) |
|
INT ([number | string [, base]) |
|
Len (s) |
|
List ([iterable]) |
|
Oct (X) |
|
Ord (c) |
|
Repr (object) |
|
Reversed (SEQ) |
|
STR ([object [, encoding [, errors]) |
|
Upper top priority Str. isalpha ()
-Whether to include only text
Code |
Result |
Print ("China ABC". isalpha ()) |
True |
Print ("". isalpha ()) |
False |
Print ("123". isalpha ()) |
False |
Print ("". isalpha ()) |
False |
Maximum top priority Str. isdecimal ()
-Whether to include only decimal numbers, including multilingual numbers
Code |
Result |
Prints ("1234567890". isdecimal ()) |
True |
Print ("\ u0660". isdecimal ()) |
True |
Print ("ABC". isdecimal ()) |
False |
Print ("". isdecimal ()) |
False |
For numbers in other languages see http://www.fileformat.info/info/unicode/category/Nd/list.htm
Upper top priority Str. isdigit ()
-Whether to include only numbers (0 ~ 9)
Code |
Result |
Print ("1234567890". isdigit ()) |
True |
Print ("\ u0660". isdigit ()) |
True |
Print ("ABC". isdigit ()) |
False |
Print ("". isdigit ()) |
False |
Maximum top priority Str. isnumeric ()
-Whether to include only numeric characters
Code |
Result |
Print ("1234567890". isnumeric ()) |
True |
Print ("\ u2155". isnumeric ()) |
True |
Print ("ABC". isnumeric ()) |
False |
Print ("". isnumeric ()) |
False |
For numeric characters, see http://www.fileformat.info/info/unicode/category/No/list.htm
Maximum top priority Str. isalnum ()
-Whether to include only text and numbers
Code |
Result |
Print ("abc123456 \ u2155". isalnum ()) |
True |
Print ("". isalnum ()) |
False |
Print ("\ t". isalnum ()) |
False |
Print ("". isalnum ()) |
False |
Maximum top priority Str. isidentifier ()
-Is it a legal identifier?
Code |
Result |
Print ("if". isidentifier ()) |
True |
Print ("China". isidentifier ()) |
True |
Print ("123". isidentifier ()) |
False |
Print ("". isidentifier ()) |
False |
Comment top comment Str. islower ()
-Whether it is in lower case
Code |
Result |
Print ("ABC". islower ()) |
True |
Print ("ABC". islower ()) |
False |
Print ("China". islower ()) |
False |
Print ("". islower ()) |
False |
Upper top priority Str. isupper ()
-Are all uppercase letters?
Code |
Result |
Print ("Hello world". istitle ()) |
True |
Print ("Hello world". istitle ()) |
False |
Print ("Hello world". istitle ()) |
False |
Print ("". istitle ()) |
False |
Upper top priority Str. istitle ()
-Whether the first letter of each word is capitalized
Code |
Result |
Print ("Hello world". istitle ()) |
True |
Print ("Hello world". istitle ()) |
False |
Print ("Hello world". istitle ()) |
False |
Print ("". istitle ()) |
False |
Wrote top response Str. isprintable ()
-Whether to include only printable characters
Code |
Result |
Print ("a B". isprintable ()) |
True |
Print ("". isprintable ()) |
True |
Print ("ABC \ t". isprintable ()) |
False |
Print ("ABC \ n". isprintable ()) |
False |
Maximum top priority Str. isspace ()
-Whether to include only white space characters
Code |
Result |
Print ("". isspace ()) |
True |
Print ("\ t \ n". isspace ()) |
True |
Print ("a B". isspace ()) |
False |
Print ("". isspace ()) |
False |
Upper top priority Str. startswith (prefix [,
Start [, end])-whether to start with prefix
Code |
Result |
Print ("Chinese". startswith ("medium ")) |
True |
Print ("Chinese". startswith ("China", "I "))) |
True |
Wrote top response Str. endswith (suffix [,
Start [, end])-whether to end with suffix
Code |
Result |
Print ("Chinese". endswith ("person ")) |
True |
Print ("Chinese". endswith ("Chinese", "I "))) |
True |
Upper top priority Str. capitalize ()
-Returns an uppercase string.
Code |
Print ("the first sentence. The second sentence.". capitalize ()) |
Result |
The first sentence. The second sentence. |
Top priority Str. Title ()
-Returns an uppercase string of each letter.
Code |
Print ("this is a title". Title ()) |
Result |
This is a title |
Using Top response Str. expandtabs ([tabsize])
-"\ T" to convert to Space
Code |
"\ T". expandtabs (8) |
Result |
'' |
Upper top priority Str. Upper ()
-Full conversion to uppercase
Code |
Print ("ABC". Upper ()) |
Result |
ABC |
Comment top comment Str. Lower ()
-Convert all data to lowercase letters.
Code |
Print ("ABC". Upper ()) |
Result |
ABC |
Upper top priority Str. Ljust (width [,
Fillchar])-align left and fill right
Code |
Print ("I". Ljust (4, "")) |
Result |
We |
Upper top priority Str. Must ust (width [,
Fillchar])-Right alignment, left Filling
Code |
Print ("I". Allowed ust (4, "= ")) |
Result |
=== Me |
Upper top priority Str. Center (width [,
Fillchar])-center, filled on both sides
Code |
Print ("I Am a split line". Center (30, "= ")) |
Result |
================ I am a split line ====================== |
Upper top priority Str. lstrip ([chars])
-Remove left white space or custom characters
Code |
'Spacious '. lstrip () |
Result |
'Spacious' |
Code |
'Www .example.com '. lstrip ('cmowz .') |
Result |
'Example. com' |
Upper top priority Str. rstrip ([chars])
-Remove right white spaces or custom characters
Code |
'Spacious '. rstrip () |
Result |
'Spacious' |
Code |
'Mississippi '. rstrip ('ipz ') |
Result |
'Mississ' |
Upper top priority Str. Strip ([chars])
-Remove blank spaces or custom characters on both sides
Code |
'Spacious '. Strip () |
Result |
'Spacious' |
Code |
'Www .example.com '. Strip ('cmowz .') |
Result |
'Example' |
Using Top response Str. swapcase ()
-Case-insensitive Conversion
Code |
Print ("ABC". swapcase ()) |
Result |
ABC |
Upper top response Str. zfill (width)
-Fill the left side with 0 to the specified width, which is generally used to modify numbers.
Code |
Print ("15". zfill (8 )) |
Result |
00000015 |
Code |
Print ("-15". zfill (8 )) |
Result |
-0000015 |
Running Top response Str. Count (sub [,
Start [, end])-calculates the number of sub occurrences between [start, end ).
Code |
Print ("abababab". Count ("Abab ") |
Result |
2 |
Note: non-overlapping count, so the result is 2 instead of 3
1.4 datetime. datetime
Obtain the current time and output it using a string.
Format: % Y-% m-% d % H: % m: % s'
Datetime. datetime. Now (). strftime ('% Y-% m-% d % H: % m: % s ')
Obtains the current time, but only retains the date.
Datetime. datetime. Now (). Date ()
Convert string to datetime type
Input string format: '% Y-% m-% d'
Datetime. datetime. strptime (time, '% Y-% m-% D ')
Print 'start at: ', datetime. datetime. Now (). strftime (' % Y-% m-% d % H: % m: % S. % F ')
Print 'start at: ', time. strftime ('% Y-% m-% d % H: % m: % S. % F', time. localtime (time. time ()))
Appendix:
Formatted symbol Summary
% A: weekday name, abbr.
% A full name of the day of the week
Abbreviated month name, abbr.
% B full name of month name
% C standard date string complete Date and Time Representation
% D day of the month in decimal format
% H hour in the 24-hour format (24-hour clock)
% I hour in 12-hour format (12-hour clock)
% J day of the year in decimal format
Month number in % m decimal format
% M decimal representation of minutes minute number
% S decimal second number
% U indicates the week of the year. Sunday is regarded as the first day (value ranges from 0 to 53) Week number (Sunday first weekday)
% W decimal indicates the day of the week (the value ranges from 0 to 6, and Sunday is 0) weekday number
% W indicates the week of the year. Monday is regarded as the first day (from 0 to 53) Week number (Monday first weekday)
% X standard date string complete date representation (e.g. 13/01/08)
% X standard time string complete time representation (e.g. 17:02:10)
% Y decimal year without Century (value ranges from 0 to 99) year number within Century
% Y indicates the tenth year number of the century section.
% Z, % Z Time Zone name. If the time zone name cannot be obtained, an empty character is returned. Name of Time Zone
% Percent sign