【python】python入门之自带help功能初步使用

阳光穿透心脏的1/2处 2024-03-25 17:13 11阅读 0赞

## python help使用 ##

C:\Users\wusong>python
    Python 3.8.2rc1 (tags/v3.8.2rc1:8623e68, Feb 11 2020, 10:46:21) [MSC v.1916 64 bit (AMD64)] on win32
    Type "help", "copyright", "credits" or "license" for more information.
    >>>

输入`help()`

>>> help
    Type help() for interactive help, or help(object) for help about object.
    >>> help()
    
    Welcome to Python 3.8's help utility!
    
    If this is your first time using Python, you should definitely check out
    the tutorial on the Internet at https://docs.python.org/3.8/tutorial/.
    
    Enter the name of any module, keyword, or topic to get help on writing
    Python programs and using Python modules.  To quit this help utility and
    return to the interpreter, just type "quit".
    
    To get a list of available modules, keywords, symbols, or topics, type
    "modules", "keywords", "symbols", or "topics".  Each module also comes
    with a one-line summary of what it does; to list the modules whose name
    or summary contain a given string such as "spam", type "modules spam".
    
    help>

这句话：To get a list of available modules, keywords, symbols, or topics, type “modules”, “keywords”, “symbols”, or “topics”.

意思就是：

要获取可用模块、关键字、符号或主题的列表，请键入 “模块”、“关键字”、“符号”或“主题”。

### modules ###

我们先看下modules

在help模式下输入：modules

help> modules
    
    Please wait a moment while I gather a list of all available modules...
    
    D:\software_install\python\lib\pkgutil.py:92: UserWarning: The numpy.array_api submodule is still experimental. See NEP 47.
      __import__(info.name)
    PIL                 asyncpg             idna                selenium
    PyInstaller         atexit              imaplib             serial
    PyQt5               atlastk             imghdr              setuptools
    __future__          attr                imp                 shelve
    _abc                attrs               importlib           shlex
    _ast                audioop             inspect             shutil
    _asyncio            backports           io                  signal
    _bisect             base64              ipaddress           simplejson
    _blake2             bcrypt              itertools           site
    _bootlocale         bdb                 jinja2              six
    _bz2                billiard            json                smtpd
    _cffi_backend       binascii            keyword             smtplib
    _codecs             binhex              kiwisolver          sndhdr
    _codecs_cn          bisect              kombu               sniffio
    _codecs_hk          broadcaster         lib2to3             socket
    _codecs_iso2022     builtins            libfuturize         socketserver
    _codecs_jp          bz2                 libpasteurize       socks
    _codecs_kr          cProfile            linecache           sockshandler
    _codecs_tw          calendar            locale              sortedcontainers
    _collections        celery              logging             sqlalchemy
    _collections_abc    certifi             loguru              sqlite3
    _compat_pickle      cffi                lzma                sqlparse
    _compression        cgi                 mailbox             sre_compile
    _contextvars        cgitb               mailcap             sre_constants
    _csv                charset_normalizer  markupsafe          sre_parse
    _ctypes             chunk               marshal             ssl
    _ctypes_test        click               math                starlette
    _datetime           click_didyoumean    matplotlib          stat
    _decimal            click_plugins       mimetypes           statistics
    _dummy_thread       click_repl          mmap                string
    _elementtree        cmath               modulefinder        stringprep
    _functools          cmd                 msilib              struct
    _hashlib            code                msvcrt              subprocess
    _heapq              codecs              multiprocessing     sunau
    _imp                codeop              nacl                symbol
    _io                 collections         netrc               symtable
    _json               colorama            nntplib             sys
    _locale             colorsys            nt                  sysconfig
    _lsprof             compileall          ntpath              tabnanny
    _lzma               concurrent          nturl2path          tarfile
    _markupbase         configparser        numbers             telnetlib
    _md5                contextlib          numpy               tempfile
    _msi                contextvars         opcode              test
    _multibytecodec     contourpy           operator            textwrap
    _multiprocessing    copy                optparse            tftpy
    _opcode             copyreg             ordered_set         this
    _operator           crypt               ordlookup           threading
    _osx_support        cryptography        os                  time
    _overlapped         csv                 outcome             timeit
    _pickle             ctypes              packaging           tkinter
    _py_abc             curses              paramiko            token
    _pydecimal          cv2                 parser              tokenize
    _pyinstaller_hooks_contrib cycler              past                tortoise
    _pyio               databases           pathlib             trace
    _queue              dataclasses         pdb                 traceback
    _random             datetime            pefile              tracemalloc
    _ruamel_yaml        dateutil            peutils             trio
    _sha1               dbm                 pickle              trio_websocket
    _sha256             decimal             pickletools         tty
    _sha3               deepdiff            pip                 turtle
    _sha512             difflib             pipes               turtledemo
    _signal             dis                 pkg_resources       types
    _sitebuiltins       distlib             pkgutil             typing
    _socket             distutils           platform            typing_extensions
    _sqlite3            django              platformdirs        tzdata
    _sre                doctest             plistlib            unicodedata
    _ssl                dotenv              poplib              unittest
    _stat               dummy_threading     posixpath           urllib
    _statistics         easy_install        pprint              urllib3
    _string             email               prettytable         uu
    _strptime           encodings           profile             uuid
    _struct             ensurepip           prompt_toolkit      uvicorn
    _symtable           enum                pstats              venv
    _testbuffer         errno               psutil              vine
    _testcapi           fastapi             pty                 virtualenv
    _testconsole        faulthandler        py_compile          warnings
    _testimportmultiple filecmp             pyclbr              watchfiles
    _testmultiphase     fileinput           pycparser           wave
    _thread             filelock            pydantic            wcwidth
    _threading_local    fnmatch             pydoc               weakref
    _tkinter            fontTools           pydoc_data          webbrowser
    _tracemalloc        formatter           pyecharts           websockets
    _warnings           fractions           pyexpat             win32_setctime
    _weakref            ftplib              pylab               win32ctypes
    _weakrefset         functools           pyparsing           winreg
    _winapi             future              pyqt5_plugins       winsound
    _xxsubinterpreters  gc                  pyqt5_tools         wsgiref
    _yaml               genericpath         pytz                wsproto
    abc                 getopt              qt5_applications    xdrlib
    aifc                getpass             qt5_tools           xlrd
    altgraph            gettext             queue               xlwt
    amqp                glob                quopri              xml
    antigravity         greenlet            random              xmlrpc
    anyio               gzip                re                  xxsubtype
    argparse            h11                 reprlib             yaml
    array               hashlib             requests            zipapp
    asgiref             heapq               rlcompleter         zipfile
    ast                 hmac                runpy               zipimport
    async_generator     html                sched               zlib
    asynchat            http                secrets
    asyncio             httptools           select
    asyncore            idlelib             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".
    
    help>

从这里可以看出还是有相当多的模块，比如我们常用的`re`,`xlrd`当然也有我们后期安装的；挑一个进去看看，有啥风景，就挑`xlrd`

help> xlrd
    Help on package xlrd:
    
    NAME
        xlrd
    
    DESCRIPTION
        # Copyright (c) 2005-2012 Stephen John Machin, Lingfo Pty Ltd
        # This module is part of the xlrd package, which is released under a
        # BSD-style licence.
    
    PACKAGE CONTENTS
        biffh
        book
        compdoc
        formatting
        formula
        info
        sheet
        timemachine
        xldate
    
    FUNCTIONS
        count_records(filename, outfile=<colorama.ansitowin32.StreamWrapper object at 0x000001D26AC13D00>)
            For debugging and analysis: summarise the file's BIFF records.
            ie: produce a sorted file of ``(record_name, count)``.
    
            :param filename: The path to the file to be summarised.
            :param outfile: An open file, to which the summary is written.
    
    -- More  -- 行数:

这里面会详细介绍`xlrd`模块的名字，描述，模块目录、功能、版本、文件位置等信息，在最后一行看到`-- More --`，这是一个分页符，表示当前页面不能全部显示所有信息，需要部分分页操作，可以使用空格键切换下一页，也可以使用回车键看下一行，看你自己的需求进行操作，如果不想看了可输入`q`退出阅读模式，进入help模式，再输入`q`则可以继续退出help模式；

help> q
    
    You are now leaving help and returning to the Python interpreter.
    If you want to ask for help on a particular object directly from the
    interpreter, you can type "help(object)".  Executing "help('string')"
    has the same effect as typing a particular string at the help> prompt.
    >>>

### keywords ###

再看下我们后面会常说的关键字

help> keywords
    
    Here is a list of the Python keywords.  Enter any keyword to get more help.
    
    False               class               from                or
    None                continue            global              pass
    True                def                 if                  raise
    and                 del                 import              return
    as                  elif                in                  try
    assert              else                is                  while
    async               except              lambda              with
    await               finally             nonlocal            yield
    break               for                 not

### symbols ###

这个是罗列了我们在python语言中涉及的运算符

help> symbols
    
    Here is a list of the punctuation symbols which Python assigns special meaning
    to. Enter any symbol to get more help.
    
    !=                  +                   <=                  __
    "                   +=                  <>                  `
    """                 ,                   ==                  b"
    %                   -                   >                   b'
    %=                  -=                  >=                  f"
    &                   .                   >>                  f'
    &=                  ...                 >>=                 j
    '                   /                   @                   r"
    '''                 //                  J                   r'
    (                   //=                 [                   u"
    )                   /=                  \                   u'
    *                   :                   ]                   |
    **                  <                   ^                   |=
    **=                 <<                  ^=                  ~
    *=                  <<=                 _

ok，差不多就简单的到这了，里面具体的内容还需要在后期使用过程中发现，modules里面的内容是最多的，当然即使你不看这些东西也不影响你学习python，这些都是都是辅助~~~