Built-in Modules in Python
The Python interpreter has a number of built-in functions. They are loaded automatically as the interpreter starts and are always available. Many of them have been discussed in previous tutorials. For example, print() and input() for I/O, number conversion functions int(), float(), complex(), data type conversions list(), tuple(), set(), etc.
In addition to built-in functions, a large number of pre-defined functions are also available as a part of libraries bundled with Python distributions. These functions are defined in modules.
A module is a file containing definitions of functions, classes, variables, constants or any other Python objects. Contents of this file can be made available to any other program.
Built-in modules are written in C and integrated with the Python interpreter. Each built-in module contains resources for certain system-specific functionalities such as OS management, disk IO, etc.
The standard library also contains many Python scripts (with the .py extension) containing useful utilities.
To display a list of all available modules, use the following command in the Python console:
>>> help('modules')
Please wait a moment while I gather a list of all available modules...
IPython _weakrefset heapq secrets
__future__ _winapi hmac select
_abc abc html selectors
_ast aifc http setuptools
_asyncio antigravity idlelib shelve
_bisect argparse imaplib shlex
_blake2 array imghdr shutil
_bootlocale ast imp signal
_bz2 asynchat importlib simplegeneric
_codecs asyncio ind site
_codecs_cn asyncore inspect six
_codecs_hk atexit io smtpd
_codecs_iso2022 audioop ipaddress smtplib
_codecs_jp autoreload ipython_genutils sndhdr
_codecs_kr backcall itertools socket
_codecs_tw base64 jedi socketserver
_collections bdb json sqlite3
_collections_abc binascii keyword sre_compile
_compat_pickle binhex lib2to3 sre_constants
_compression bisect linecache sre_parse
_contextvars builtins locale ssl
_csv bz2 logging stat
_ctypes cProfile lzma statistics
_ctypes_test calendar macpath storemagic
_datetime cgi mailbox string
_decimal cgitb mailcap stringprep
_distutils_findvs chunk marshal struct
_dummy_thread cmath math subprocess
_elementtree cmd mimetypes sunau
_functools code mmap symbol
_hashlib codecs modulefinder sympyprinting
_heapq codeop msilib symtable
_imp collections msvcrt sys
_io colorama multiprocessing sysconfig
_json colorsys netrc tabnanny
_locale compileall nntplib tarfile
_lsprof concurrent nt telnetlib
_lzma configparser ntpath tempfile
_markupbase contextlib nturl2path test
_md5 contextvars numbers tests
_msi copy opcode textwrap
_multibytecodec copyreg operator this
_multiprocessing crypt optparse threading
_opcode csv os time
_operator ctypes parser timeit
_osx_support curses parso tkinter
_overlapped cythonmagic pathlib token
_pickle dataclasses pdb tokenize
_py_abc datetime pickle trace
_pydecimal dbm pickleshare traceback
_pyio decimal pickletools tracemalloc
_queue decorator pip traitlets
_random difflib pipes tty
_sha1 dis pkg_resources turtle
_sha256 distutils pkgutil turtledemo
_sha3 doctest platform types
_sha512 dummy_threading plistlib typing
_signal easy_install poplib unicodedata
_sitebuiltins email posixpath unittest
_socket encodings pprint urllib
_sqlite3 ensurepip profile uu
_sre enum prompt_toolkit uuid
_ssl errno pstats venv
_stat faulthandler pty warnings
_string filecmp py_compile wave
_strptime fileinput pyclbr wcwidth
_struct fnmatch pydoc weakref
_symtable formatter pydoc_data webbrowser
_testbuffer fractions pyexpat winreg
_testcapi ftplib pygments winsound
_testconsole functools queue wsgiref
_testimportmultiple gc quopri xdrlib
_testmultiphase genericpath random xml
_thread getopt re xmlrpc
_threading_local getpass reprlib xxsubtype
_tkinter gettext rlcompleter zipapp
_tracemalloc glob rmagic zipfile
_warnings gzip runpy zipimport
_weakref hashlib sched zlib
Enter any module name to get more help. Or, type "modules spam" to search
for modules whose name or summary contain the string "spam".
Learn about some of the frequently used built-in modules in the next few chapters.