Python common modules ingest

Time module:

in Python, there are usually several ways to represent the time:

1, time stamp, such as Time.time

2. Formatted time string, e.g. ' 17/01/2017 10:17:00 '

3, tuples (struct_time), such as Gmtime, localtime, etc.

Time.time (): Converts all time from 1970 to present to the number of seconds, i.e. timestamp

Time.gmtime (): Converts the timestamp (in seconds) to the tuple form of the UTC time Zone

Time.localtime (): Converts a timestamp into a tuple form in the local time zone

This tuple form of time can be achieved through its internal method of the required time element. Cases:

x = Time.localtime ()

X.tm_year can get what year it is now

X.tm_mon can get the current month

X.tm_mday can get the current day

Time.sleep (s): sleep s S

Time.mktime (t): Convert time in tuple (tuple) to timestamp

Time.strftime (format [, tuple]):

Converts the time in the form of a tuple to a formatted time string (displayed numerically) and converts the current localtime if no tuple is specified

Time.strptime (String, format): Converts a formatted time string to a time in the form of a Narimoto group

Time.asctime ([tuple]):

Converts the time of the tuple form to a formatted time string (shown in English) and converts the current localtime if no tuple is specified

Time.ctime ([seconds]):

Converts the timestamp to a formatted time string (shown in English) and converts the current timestamp if no time stamp is specified

DateTime module:

Datetime.datetime.now (): Gets the current date and time

Datetime.datetime.now () + Datetime.datetime.delta (3): Current time after three days

Datetime.datetime.now () + Datetime.datetime.delta (-3): Current time made three days ago

Datetime.datetime.now () + Datetime.datetime.delta (hours=3): Gets the current time after three hours

Datetime.datetime.now () + Datetime.datetime.delta (hours=-3): Get current time three hours ago

Datetime.datetime.now (). Replace (minute=10,hour=10): Time substitution

Random module: Stochastic number

Random.random (): Gets a floating-point random number between 0-1

Random.uniform (1,10): Gets a floating-point random number between 1-10, 1 and 10 can be arbitrarily specified

Random.randint (1,3): get arbitrary random numbers between 1-3, including 1 and 3, where 1 and 3 can be arbitrarily specified

Random.randrange (1,3): obtain arbitrary random numbers between 1-3, excluding 3, where 1 and 3 can be arbitrarily specified

Random.choice (' equence): Randomly take an element from the sequence sequence

Random.sample (Sequence,count): Random count of elements from sequence sequence each time

Random.shuffle (Sequence): Shuffle, disrupt the order of a sequence

OS module: Provides an interface for invoking the operating system

OS.GETCWD (): Gets the current working directory

Os.chdir (PATH): Switch directory

Os.curdir: Returns the current directory

Os.pardir: Returns the parent directory of the current directory

Os.makedirs (name, mode=511, Exist_ok=false): Create a directory recursively

Example: Os.makedirs (R '/a/b/c/d/e ')

Os.removedirs (name): If the directory is empty then delete, and recursively to the previous level of the directory, if it is empty then delete, and so on

Os.mkdir (Path, mode=511, *, Dir_fd=none): Creates a single-level directory that throws an exception if the parent directory does not exist

Os.rmdir (Path, *, Dir_fd=none): Deletes a single-level empty directory and throws an exception if the directory is not empty

Os.listdir (Path=none): Lists all files under a path, including files and directories

Os.remove (): Delete a file

Os.rename (' oldname ', ' newname '): Renaming files/directories

Os.stat (' Path/to/filename '): Get File/directory information

OS.SEP: Output operating system-specific path delimiter, win under ' \ \ ', Linux for '/'

OS.LINESEP: Output The line terminator used by the current platform, win under ' \ r \ n ', Linux for ' \ n '

OS.PATHSEP: Outputs a string used to split the path of a file, separating different paths when storing multiple paths

Os.name: The output string indicates the current usage platform. Win--> ' nt ',linux--> ' POSIX '

Os.system (' Bash Command '): Run the shell command to display the results directly

Os.environ: Getting system environment variables

Os.path.abspath (PATH): Returns the absolute path normalized by path

Os.path.split (PATH): Returns a 2-element tuple that splits the path into directories and filenames as elements

Os.path.dirname (PATH): Returns the directory of path. is actually the first element of Os.path.split (path)

Os.path.basename (PATH): Returns the last file name of path. If path ends with a/or \, then a null value is returned.

is actually the second element of Os.path.split (path)

Os.path.exists (PATH): Determines if path exists, exists return true, otherwise returns false

Os.path.isabs (PATH): Determines if path is an absolute path, returns true, otherwise false

Os.path.isfile (PATH): Determines if path is not a file, yes returns true, otherwise false

Os.path.isdir (PATH): Determines if path is a directory, yes returns TRUE, otherwise returns false

Os.path.join (path1 [, path2 [, ...]) ：

When multiple paths are combined, the parameters before the first absolute path are ignored

Os.path.getatime (PATH): Returns the last access time of the file or directory to which path is pointing

Os.path.getmtime (PATH): Returns the last modified time of the file or directory to which path is pointing

SYS module:

SYS.ARGV: Command line argument list, the first element is the path of the program itself

Sys.exit (N): Exit program, Exit normally (0)

Sys.version: Get version information for Python interpreter

Sys.maxint: the largest int value

Sys.path: Returns the search path for the module, using the value of the PYTHONPATH environment variable when initializing

Sys.platform: Returns the operating system platform name

Sys.stdout.write (' please: ')

VA1 = Sys.stdin.readline () [:-1]

Shutil: Specially used to copy files, can compress package

Shutil.copyfileobj (fsrc,fdst [, length]):

Copy the contents of the FFSRC to the FDST, and you can set the number of copies by length.

Shutil.copyfile (SRC,DST): copy src to DST

Shutil.copymode (SRC,DST): Copy only permission. The content, group, and user of the new file are the same (who created the file)

Shutil.copystat (SRC,DST): Copy status information, including mode Bits,atime,mtime,flags

Shutil.copy (SRC,DST): Copying Files and Permissions

Shutil.copy2 (SRC,DST): Copying Files and status information

Shutil.copytree (src,dst,symlink=false,ignore=none): Recursive de-Copying files

Shutil.rmtree (path [, ignore_errors [, OnError]): To remove files recursively

Shutil.move (SRC,DST): To move files recursively

Shutil.make_archive (Base_name,format,...) : Create a compressed package and return the file path, for example: Zip, tar

Base_name:

The file name of the compressed package, or the path to the compressed package. Only the file name is saved to the current directory, otherwise it is saved to the specified path.

For example: www + = Save to Current path

such as:/users/sean/www = Save to/users/sean/www

Format: Compressed package type. ' Zip ', ' tar ', ' bztar ', ' Gztar '

Root_dir: directory path to compress (default current directory)

Owner: User. Default Current User

Group: Groups. Default Current Group

Logger: Used to log logs. Usually a logging. Logger Object

Shutil Processing of compressed packets is done by calling the ZipFile and Tarfile two modules.

ZipFile module:

Compression:

z = zipfile. ZipFile (' Test.zip ', ' W ')

Z.write (' A.log ')

Z.write (' Data.data ')

Z.close ()

Extract:

z = zipfile. ZipFile (' Test.zip ', ' R ')

Z.extractall ()

Z.close ()

Tarfile module:

Compression:

tar = Tarfile.open (' Your.tar ', ' W ')

Tar.add ('/users/sean/www.zip ', arcname= ' Www.zip ')

Tar.add ('/users/sean/cmdb.zip ', arcname= ' Cmdb.zip ')

Tar.close ()

Extract:

tar = Tarfile.open (' Your.tar ', ' R ')

Tar.extractall ()

Tar.close ()

JSON & Pickle: Two modules for serialization

JSON, used to convert between string and Python data types

Converts data types in Python memory to strings stored on hard disk files

It solves the problem of data exchange between different languages and different platforms.

Pickle for conversion between Python-specific types and Python data types

Converts any data type in Python memory to a string stored on a file on the hard disk

Both provide four functions: dumps, dump, loads, load

Shelve: A Simple dictionary-type (key,value) module that stores memory data through file persistence

Can persist any Python data types that pickle can support

Write:

D = Shelve.open (' shelve_test ') #打开一个文件class Test (object):d EF __init__ (self,n): SELF.N = NT = Test (123) t2 = Test (1234567) name = [' Tom ', ' Jerry ', ' Test ']d[' test '] = name #持久化列表d [' t1 '] = t #持久化类d [' t2 '] = T2d.close ()

Read:

D.get (' Test ') d.get (' T1 ') d.get (' T2 ')

XML: Used to process XML in Python

Import Xml.etree.ElementTree as Ettree = Et.parse (' xmltest.xml ') #要处理的文件名root = Tree.getroot () print (Root.tag) #打印根标签名 # Traverse the XML document for the child in Root:print (Child.tag,child.attrib) for I in Child:print (I.tag,i.text) #只遍历year节点for node in Root.iter (' year '):p rint (Node.tag,node.text) #修改for node in Root.iter (' year '): new_year = Int (node.text) + 1node.text = str (new_ Year) Node.set ("Updated_by", "Sean") Tree.write (' Xmltest.xml ') #删除nodefor country in Root.findall (' Country '): rank = int (Country.find (' rank '). Text) if rank > 50:root.remove (Country) tree.write (' Output.xml ')

Configparser: Generating and modifying common configuration documents

Generated:

Import Configparserconfig = Configparser. Configparser () config[' DEFAULT ' = {' serveraliveinterval ': ' A ', ' Compression ': ' Yes ', ' compressionlevel ': ' 9 '}config[ ' bitbucket.org ' = {}config[' bitbucket.org ' [' User '] = ' HG ' config[' topsecret.server.com '] = {}topsecret = config[' Topsecret.server.com ']topsecret[' Host Port '] = ' 50022 ' topsecret[' ForwardX11 '] = ' no ' config[' DEFAULT ' [' ForwardX11 '] = ' Yes ' with open (' Example.ini ', ' W ') as Configfile:config.write (ConfigFile)

Read:

conf = Configparser. Configparser () conf.read (' Example.ini ') print (Conf.defaults ()) print (conf[' bitbucket.org ' [' User '])

Hashlib: For encryption-related operations

The 3.x series replaces the MD5 module and the SHA module in the 2.x series. Mainly provides SHA1, SHA224, SHA256, SHA284, SHA512 and MD5 algorithms

Import HASHLIBM = Hashlib.md5 () m.update (b ' Hello ') m.update (b "It ' s Me") print (M.digest ()) #二进制格式hashprint (M.hexdigest ( )) #十六进制格式hash

Note: The result of the previous two update before printing, the result is two times the object of the update is added together to generate the hash

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Python common modules ingest