simply open the python shell and type help('modules'). You will get a list of all built-in modules.
Python 3.7.4 (tags/v3.7.4:e09359112e, Jul 8 2019, 19:29:22) [MSC v.1916 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license()" for more information.
>>> help('modules')
Please wait a moment while I gather a list of all available modules...
Python 3.7.4 (tags/v3.7.4:e09359112e, Jul 8 2019, 19:29:22) [MSC v.1916 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license()" for more information.
>>> help('modules')
Please wait a moment while I gather a list of all available modules...
__future__ atexit http scrolledlist
__main__ audioop hyperparser search
_abc autocomplete idle searchbase
_ast autocomplete_w idle_test searchengine
_asyncio autoexpand idlelib secrets
_bisect base64 imaplib select
_blake2 bdb imghdr selectors
_bootlocale binascii imp setuptools
_bz2 binhex importlib shelve
_codecs bisect inspect shlex
_codecs_cn browser io shutil
_codecs_hk builtins iomenu signal
_codecs_iso2022 bz2 ipaddress site
_codecs_jp cProfile itertools smtpd
_codecs_kr calendar json smtplib
_codecs_tw calltip keyword sndhdr
_collections calltip_w lib2to3 socket
_collections_abc cgi linecache socketserver
_compat_pickle cgitb locale sqlite3
_compression chunk logging squeezer
_contextvars cmath lzma sre_compile
_csv cmd macosx sre_constants
_ctypes code macpath sre_parse
_ctypes_test codecontext mailbox ssl
_datetime codecs mailcap stackviewer
_decimal codeop mainmenu stat
_dummy_thread collections marshal statistics
_elementtree colorizer math statusbar
_functools colorsys mimetypes string
_hashlib compileall mmap stringprep
_heapq concurrent modulefinder struct
_imp config msilib subprocess
_io config_key msvcrt sunau
_json configdialog multicall symbol
_locale configparser multiprocessing symtable
_lsprof contextlib netrc sys
_lzma contextvars nntplib sysconfig
_markupbase copy nt tabnanny
_md5 copyreg ntpath tarfile
_msi crypt nturl2path telnetlib
_multibytecodec csv numbers tempfile
_multiprocessing ctypes opcode test
_opcode curses operator textview
_operator dataclasses optparse textwrap
_osx_support datetime os this
_overlapped dbm outwin threading
_pickle debugger paragraph time
_py_abc debugger_r parenmatch timeit
_pydecimal debugobj parser tkinter
_pyio debugobj_r pathbrowser token
_queue decimal pathlib tokenize
_random delegator pdb tooltip
_sha1 difflib percolator trace
_sha256 dis pickle traceback
_sha3 distutils pickletools tracemalloc
_sha512 doctest pip tree
_signal dummy_threading pipes tty
_sitebuiltins dynoption pkg_resources turtle
_socket easy_install pkgutil turtledemo
_sqlite3 editor platform types
_sre email plistlib typing
_ssl encodings poplib undo
_stat ensurepip posixpath unicodedata
_string enum pprint unittest
_strptime errno profile urllib
_struct faulthandler pstats uu
_symtable filecmp pty uuid
_testbuffer fileinput py_compile venv
_testcapi filelist pyclbr warnings
_testconsole fnmatch pydoc wave
_testimportmultiple formatter pydoc_data weakref
_testmultiphase fractions pyexpat webbrowser
_thread ftplib pyparse window
_threading_local functools pyshell winreg
_tkinter gc query winsound
_tracemalloc genericpath queue wsgiref
_warnings getopt quopri xdrlib
_weakref getpass random xml
_weakrefset gettext re xmlrpc
_winapi glob redirector xxsubtype
abc grep replace zipapp
aifc gzip reprlib zipfile
antigravity hashlib rlcompleter zipimport
argparse heapq rpc zlib
array help rstrip zoomheight
ast help_about run zzdummy
asynchat history runpy
asyncio hmac runscript
asyncore html sched
