1. os module
1、os.getcwd()
Get the current working directory (the current working directory is the folder where the current file is located by default)
import them print(os.getcwd())
2、os.chdir(path)
Change the current working directory, the os.chdir() parameter is the path
import them print(os.getcwd()) print(os.chdir(r"d:\python\exercise\test_package\a")) print(os.getcwd())
output result
D:\06python\exercise\test_package None d:\06python\exercise\test_package\a #You can see that the working path has changed
3、os.curdir os.pardir
os.curdir Returns the current directory: ('.') os.pardir Gets the parent directory string name of the current directory: ('..')
import them print(os.curdir) print(os.pardir)
output result
. ..
4、os.makedirs("dirname1/dirname2")
Can generate multi-level recursive directories
import them os.makedirs(r"exercise\a\b\c")
output result
5、os.removedirs(”dirname1“）
Recursively delete folders must be empty directories. If the directory is empty, delete it and recurse to the previous directory. If it is also empty, delete it, and so on.
import them os.removedirs(r"exercise\a\b\c")
output result
6、os.mkdir('dirname')
Generate a single-level directory; equivalent to mkdir dirname in the shell
import them
os.mkdir("a")
output result
7、os.rmdir('dirname')
Delete a single-level empty directory. If the directory is not empty, it cannot be deleted, and an error is reported; it is equivalent to rmdir dirname in the shell
import them
os.rmdir("a")
# os.rmdir("b")
output result
8、os.listdir('dirname')
List all files and subdirectories in the specified directory, including hidden files, and print them in a list
import them
print(os.listdir("a"))
output result
9、os.remove()
delete a file
import them
os.remove("a/x.py")
output result
10、os.rename("oldname","newname")
rename file/directory
Use os.rename() under Linux platform, os.rename cannot be used directly under Windows platform, use os.replace() under Windows platform,
import them
os.rename("test.py","new_test.py")
output result
11、os.stat('path/filename')
Get file/directory information
import them
print(os.stat("test.py"))
output result
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st_mode: inode protection mode
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st_ino: inode node number.
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st_dev: The device where the inode resides.
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st_nlink: The number of links for the inode.
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st_uid: User ID of the owner.
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st_gid: The owner's group ID.
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st_size: Size of normal files in bytes; contains data waiting for some special files.
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st_atime: The time of the last visit.
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st_mtime: The time of the last modification.
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st_ctime: "ctime" as reported by the operating system. On some systems (like Unix) the time of the last metadata change, on others (like Windows) the time of creation.
12 、 os.sep
Output the OS-specific path separator, " \ " under win, "/" under Linux
import them print(os.sep)
output result
13 os.linesep
Output the line terminator used by the current platform, "\r\n" under win, "\n" under Linux
14、os.pathsep
The output string used to split the file path is; under win, and under Linux:
15、os.name
The output string indicates the currently used platform. win->'nt'; Linux->'posix'
16、os.system("bash command") os.popen("bash command“)
os.system("bash command") run the shell command and display it directly
os.popen("bash command") run the shell command and get the execution result
17 、 os.environ
Get system environment variables
18、os.path.abspath(path)
Returns the absolute path normalized by path, including the filename
import them print(os.path.abspath(__file__))
output result
19、os.path.split(path)
When path is the absolute path of the file, split the path into a directory and a filename 2-tuple to return
When path is the absolute path of a file directory (like "D:\06python\exercise\test_package"), os.path.split() splits the path into the last folder as a part, and the other as a part in front
import them print(os.path.split(__file__))
output result
Example 2
import them print(os.path.split(r"D:\06python\exercise\test_package"))
output result
20、os.path.dirname(path)
Returns the directory of path. In fact, it is the first element of os.path.split(path).
When the parameter path is a file, os.path.dirname() is the directory part of the complete absolute path to get the file (remove the file name)
When the parameter path is a directory, os.path.dirname() obtains the directory part of the complete path, and obtains the absolute path of the upper-level directory
os.path.dirname(os.path.dirname(path)) is the upper-level directory obtained and returned to the directory, that is, the absolute value of the upper-level directory of the specified directory (the result of os.path.dirname(path)). path
import them print(os.path.abspath(__file__)) print(os.path.dirname(__file__)) print(os.path.dirname(os.path.dirname(__file__)))
output result
Analysis: The last two output results here are slashes, and the first os.path.abspath output is the common backslashes in the win platform, the reason is the optimization done by pycharm
small experiment
As can be seen from this result, the result of using the python interpreter directly is still backslashes
The same file is executed in pycharm, and the output in pycharm is the slash
21、os.path.basename(path)
When the parameter path is the absolute path of the file, it returns the last file name of path. If path ends with / or \, then it will return a null value. That is, the second element of os.path.split(path).
When the parameter path is an absolute path of a file directory (like "D:\06python\exercise\test_package"), the name of the last folder is returned
22、os.path.exists(path)
Determine whether the file or directory exists, if the path exists, return True; if the path does not exist, return False
23、os.path.isabs(path)
Return True if path is an absolute path
import them print(os.path.isabs(r"D:\06python\exercise\test_package\test.py")) print(os.path.isabs(r".\test_package\test.py")) print(os.path.isabs(__file__)) v =os.path.isabs(r"D:\06python\exercise\test_package") print(v) print(type(v))
output result
Analysis: Here even an absolute path that does not exist will return True
24、os.path.isfile(path)
Returns True if path is an existing file. Otherwise return False
import them print(os.path.isfile(r"D:\06python\exercise\test_package\test.py")) print(os.path.isfile(r"D:\06python\exercise\test_package\t.py")) v =os.path.isfile(r"D:\06python\exercise\test_package") print(v) print(type(v))
output result
25、os.path.isdir(path)
Returns True if path is an existing directory. Otherwise return False
26、os.path.join(path1[, path2[, ...]])
Return after combining multiple paths, parameters before the first absolute path will be ignored
import them print(os.path.join(r"D:\06python\exercise",r"test_package\test.py")) print(os.path.join(r"D:\06python\exercise",r"test_package\t.py")) #Paths that do not exist can also be synthesized print(os.path.join(r"D:\06python\exercise",r"/test_package\t.py")) """If there is a slash or backslash in the second parameter, the previous parameter will be ignored i.e. the parameter before the first absolute path will be ignored""" print(os.path.join(r"D:\06python\exercise","test_package"))
output result
27、os.path.getatime(path)os.path.getmtime(path)
os.path.getatime(path) Returns the last access time of the file or directory pointed to by path os.path.getmtime(path) Returns the last modification time of the file or directory pointed to by path
import them print(os.path.getatime(__file__)) # Returns the last access time of the file or directory pointed to by path print(os.path.getmtime(__file__)) # Returns the last modification time of the file or directory pointed to by path print(os.path.getatime(r"D:\06python\exercise\test_package")) print(os.path.getmtime(r"D:\06python\exercise\test_package"))
output result
28、os.path.getsize(path)
Returns the size of path (file or all files in a directory)
import them print(os.path.getsize(__file__)) print(os.path.getsize(r"D:\06python\exercise\test_package"))
output result
