>>> help("modules")
Please wait a moment while I gather a list of all available modules...
1 abc html setuptools
__future__ aifc http shelve
_ast antigravity idlelib shlex
_bisect argparse imaplib shutil
_bootlocale array imghdr signal
_bz2 ast imp site
_codecs asynchat importlib smtpd
_codecs_cn asyncio inspect smtplib
_codecs_hk asyncore io sndhdr
_codecs_iso2022 atexit ipaddress socket
_codecs_jp audioop itertools socketserver
_codecs_kr base64 json sqlite3
_codecs_tw bdb keyword sre_compile
_collections binascii lib2to3 sre_constants
_collections_abc binhex linecache sre_parse
_compat_pickle bisect locale ssl
_compression builtins logging stat
_csv bz2 lzma statistics
_ctypes cProfile macpath string
_ctypes_test calendar macurl2path stringprep
_datetime cgi mailbox struct
_decimal cgitb mailcap subprocess
_dummy_thread chunk marshal sunau
_elementtree cmath math symbol
_functools cmd mimetypes symtable
_hashlib code mmap sys
_heapq codecs modulefinder sysconfig
_imp codeop msilib tabnanny
_io collections msvcrt tarfile
_json colorsys multiprocessing telnetlib
_locale compileall netrc tempfile
_lsprof concurrent nntplib test
_lzma configparser nt textwrap
_markupbase contextlib ntpath this
_md5 copy nturl2path threading
_msi copyreg numbers time
_multibytecodec crypt opcode timeit
_multiprocessing csv operator tkinter
_opcode ctypes optparse token
_operator curses os tokenize
_osx_support datetime parser trace
_overlapped dbm pathlib traceback
_pickle decimal pdb tracemalloc
_pydecimal difflib pickle tty
_pyio dis pickletools turtle
_random distutils pip turtledemo
_sha1 doctest pipes types
_sha256 dummy_threading pkg_resources typing
_sha512 easy_install pkgutil unicodedata
_signal email platform unittest
_sitebuiltins encodings plistlib urllib
_socket ensurepip poplib uu
_sqlite3 enum posixpath uuid
_sre errno pprint venv
_ssl faulthandler profile warnings
_stat filecmp pstats wave
_string fileinput pty weakref
_strptime fnmatch py_compile webbrowser
_struct formatter pyclbr winreg
_symtable fractions pydoc winsound
_testbuffer ftplib pydoc_data wsgiref
_testcapi functools pyexpat xdrlib
_testimportmultiple gc queue xml
_testmultiphase genericpath quopri xmlrpc
_thread getopt random xxsubtype
_threading_local getpass re zipapp
_tkinter gettext reprlib zipfile
_tracemalloc glob rlcompleter zipimport
_warnings gzip runpy zlib
_weakref hashlib sched
_weakrefset heapq select
_winapi hmac selectors
Enter any module name to get more help. Or, type "modules spam" to search
for modules whose name or summary contain the string "spam".
举例：查看某个模块的具体使用帮助：
>>> help("linecache")
Help on module linecache:
NAME
linecache - Cache lines from Python source files.
DESCRIPTION
This is intended to read lines from modules imported -- hence if a filename
is not found, it will look down the module search path for a file by
that name.
FUNCTIONS
checkcache(filename=None)
Discard cache entries that are out of date.
(This is not checked upon each call!)
clearcache()
Clear the cache entirely.
getline(filename, lineno, module_globals=None)
DATA
__all__ = ['getline', 'clearcache', 'checkcache']
FILE
c:\python3.5\lib\linecache.py