BasicOfModule.md

Modules

• A module is a Python file containing python definitions statements.
• A module can define functions, classes, and variables, Methods also contain runnable code.
• Grouping similar type of code into a file and whenever it required to use it

some python inbuilt modules

1.os
2.string
3.threading
4.sys
5.collection
6.argparse
7.sqlit3
8.raw
9.re
10.pip
.... and much more

How to Get List of Installed modules list in python?

you can write down following code into an interactive shell or in the python file

help('modules')

you will get the result

Please wait a moment while I gather a list of all available modules...

Output

FileSearchEngine    _testcapi           ftplib              reprlib
GetFiles            _testcapi_d         functools           requests
PIL                 _testconsole        gc                  rlcompleter
PyQt5               _testconsole_d      genericpath         runpy
SqliteHandler       _testimportmultiple getopt              sched
Test                _testimportmultiple_d getpass             secrets
__future__          _testmultiphase     gettext             select
_abc                _testmultiphase_d   glob                select_d
_ast                _thread             gzip                selectors
_asyncio            _threading_local    hashlib             selenium
_asyncio_d          _tkinter            heapq               setuptools
_bisect             _tkinter_d          hmac                shelve
_blake2             _tracemalloc        html                shlex
_bootlocale         _warnings           html5lib            shutil
_bz2                _weakref            http                signal
...........    ................    ...........         ....

How To import module in python program?

We can use any Python source file as a module by executing an import statement in some other Python source file.

• You can import the module using import keywords

Syntax:

import <moduleName>

Example:

#import required module
import platform

How to rename imported modules?

• as keyword is used to bind a new name to an object.
• If you import a module directly and then import the same module but with a different name via as both names will point to the same object.

Syntax:

import <moduleName> as <newObjectName>

Example

#Normal way to import a module
import platform

#using as Keyword import a module
import platform as plt

#if you check the id of object 
#platform and plt both will point to the same object
print(id(platform))
print(id(plt))

Output:

139950267344280
139950267344280

How to list all functions in a Python module?

you can use the following two different functions to achieve function names, variables, and documentation

1.help()
2.dir()

1.help()

• help() function is used to get the all function with docuemantation

Syntax:

help(moduleName)

Example:

#import module
import platform

#get documentation
print(help(platform))

Output:

Help on module platform:

NAME
    platform

MODULE REFERENCE
    https://docs.python.org/3.6/library/platform
    
DESCRIPTION
    This module tries to retrieve as much platform-identifying data as possible.
    It makes this information available via function APIs.
    
CLASSES
    builtins.tuple(builtins.object)
        uname_result
    
    class uname_result(builtins.tuple)
     |  uname_result(system, node, release, version, machine, processor)

FUNCTIONS
    architecture(executable='/usr/local/bin/python3', bits='', linkage='')
        Queries the given executable (defaults to the Python interpreter
        binary) for various architecture information.
        
        Returns a tuple (bits, linkage) which contains information about
        the bit architecture and the linkage format used for the
        executable

DATA
    DEV_NULL = '/dev/null'
    __copyright__ = '\n    Copyright (c) 1999-2000, Marc-Andre Lemburg.

VERSION
    1.0.8

FILE
    /usr/lib/python3.6/platform.py

None

2.dir()

• To simply list the names of all the functions and variables defined in the module.

Syntax:

dir(moduleName)

Example:

#import module
import platform

#get function names and variable name
print(dir(platform))

Output

['DEV_NULL', '_UNIXCONFDIR', '_WIN32_CLIENT_RELEASES', 
'_WIN32_SERVER_RELEASES', '__builtins__', '__cached__',
'__copyright__', '__doc__', '__file__', '__loader__', 
'__name__', '__package__', '__spec__', '__version__',
'_codename_file_re','_default_architecture', '_dist_try_harder',
'_distributor_id_file_re', '_follow_symlinks', 
'_ironpython26_sys_version_parser', '_ironpython_sys_version_parser', 
'_java_getprop', 
'_libc_search','_linux_distribution', '_lsb_release_version', 
'_mac_ver_xml', '_node', 
'_norm_version', '_parse_release_file','_platform', 
'_platform_cache', '_pypy_sys_version_parser',
'_release_file_re', '_release_filename', '_release_version',
'_supported_dists', '_sys_version',
'_sys_version_cache', '_sys_version_parser',
'_syscmd_file', '_syscmd_uname','_syscmd_ver',
'_uname_cache', '_ver_output', 'architecture', 
'collections', 'dist', 'java_ver', 'libc_ver', 
'linux_distribution', 'mac_ver', 'machine', 'node',
'os', 'platform', 'popen', 'processor',
'python_branch', 'python_build','python_compiler',
'python_implementation', 'python_revision',
'python_version', 'python_version_tuple', 're',
'release', 'subprocess', 'sys', 'system',
'system_alias', 'uname', 'uname_result', 'version',
'warnings', 'win32_ver']

How to use the function, methods of modules?

• if you want to check the python version from platform module there is one method called python_version()

Syntax:

moduleName.<MethodName>()

Example:

#import module
import platform

#Call python_version() from platform
version=platform.python_version()
print(version)

Output:

3.7.3

How to import a specific method or function name from Module?

Syntax:

from <moduleName> import methodName,methodName2

Example import only python_version()

#import required module
from platform import python_version

#get python version
version=python_version()
print(version)

Output:

3.7.3