pyhton中
通过如下链接学习相关基本内容，包括：基本数据类型、控制流、数据结构、模块、输入输出、异常捕获、类。
http://docs.python.org/2.7/tutorial/
1.help命令
help（类名）查看类中所有详细的功能
help（类名.函数名）查看类中某函数方法的详细内容
breath@ubuntu:~$ bpythonbpython version 0.15 on top of Python 2.7.6 /usr/bin/python2.7>>> helpType help() for interactive help, or help(object) for help about object.>>> help()Welcome to Python 2.7! This is the online help utility.If this is your first time using Python, you should definitely check outthe tutorial on the Internet at http://docs.python.org/2.7/tutorial/.Enter the name of any module, keyword, or topic to get help on writingPython programs and using Python modules. To quit this help utility andreturn to the interpreter, just type "quit".To get a list of available modules, keywords, or topics, type "modules","keywords", or "topics". Each module also comes with a one-line summaryof what it does; to list the modules whose summaries contain a given wordsuch as "spam", type "modules spam".help> qYou are now leaving help and returning to the Python interpreter.If you want to ask for help on a particular object directly from theinterpreter, you can type "help(object)". Executing "help('string')"has the same effect as typing a particular string at the help> prompt.>>> help(help)Help on _Helper in module bpython.curtsiesfrontend._internal object:class _Helper(bpython._internal._Helper) | Method resolution order: | _Helper | bpython._internal._Helper | __builtin__.object | | Methods defined here: | | __call__(self, *args, **kwargs) | | __getattribute__(...) | x.__getattribute__('name') <==> x.name | | __init__(self, repl=None) | | pager(self, output) | | ---------------------------------------------------------------------- | Methods inherited from bpython._internal._Helper: | | __repr__(self) | | ---------------------------------------------------------------------- | Data descriptors inherited from bpython._internal._Helper: | | __dict__ | dictionary for instance variables (if defined) | | __weakref__ | list of weak references to the object (if defined)~~~~~~~~~~~(END) 2.The Python Standard Library
2.1__builtin__
备注：__builtin__模块中的objects（类对象）、functions（函数方法）、data（常量）、exception（异常）可以直接使用，无需import。除了__builtin__中显示的其它所有类，都需要通过import导入才能使用。
>>> help('__builtin__')Help on built-in module __builtin__:NAME __builtin__ - Built-in functions, exceptions, and other objects.FILE (built-in)DESCRIPTION Noteworthy: None is the `nil' object; Ellipsis represents `...' in slices.CLASSES object basestring str unicode buffer bytearray classmethod complex dict enumerate file float frozenset int bool list long memoryview property reversed set slice staticmethod super tuple type xrange class basestring(object) | Type basestring cannot be instantiated; it is the base for str and unicode. | .........FUNCTIONS __import__(...) __import__(name, globals={}, locals={}, fromlist=[], level=-1) -> module Import a module. Because this function is meant for use by the Python interpreter and not for general use it is better to use importlib.import_module() to programmatically import a module. The globals argument is only used to determine the context; they are not modified. The locals argument is unused. The fromlist should be a list of names to emulate ``from name import ...'', or an empty list to emulate ``import name''. When importing a module from a package, note that __import__('A.B', ...) returns package A when fromlist is empty, but its submodule B when fromlist is not empty. Level is used to determine whether to perform absolute or relative imports. -1 is the original strategy of attempting both absolute and relative imports, 0 is absolute, a positive number is the number of parent directories to search relative to the current module. abs(...) abs(number) -> number Return the absolute value of the argument. all(...) all(iterable) -> bool Return True if bool(x) is True for all values x in the iterable. If the iterable is empty, return True. .........DATA Ellipsis = Ellipsis False = False None = None NotImplemented = NotImplemented True = True __debug__ = True copyright = Copyright (c) 2001-2014 Python Software Foundati...ematisc... credits = Thanks to CWI, CNRI, BeOpen.com, Zope Corpor...opment. ... exit = Use exit() or Ctrl-D (i.e. EOF) to exit help = Type help() for interactive help, or help(object) for help abou... license = Type license() to see the full license text quit = Use quit() or Ctrl-D (i.e. EOF) to exit(END) 2.1.1查看类class
备注：查看类对象的时候会显示类的描述，类中的方法定义。
例子1：查看int类，以及类的__add__方法。
>>> help('int')Help on class int in module __builtin__:class int(object) | int(x=0) -> int or long | int(x, base=10) -> int or long | | Convert a number or string to an integer, or return 0 if no arguments | are given. If x is floating point, the conversion truncates towards zero. | If x is outside the integer range, the function returns a long instead. | | If x is not a number or if base is given, then x must be a string or | Unicode object representing an integer literal in the given base. The | literal can be preceded by '+' or '-' and be surrounded by whitespace. | The base defaults to 10. Valid bases are 0 and 2-36. Base 0 means to | interpret the base from the string as an integer literal. | >>> int('0b100', base=0) | 4 | | Methods defined here: | | __abs__(...) | x.__abs__() <==> abs(x) | | __add__(...) | x.__add__(y) <==> x+y...... >>> help('int.__add__')Help on wrapper_descriptor in int:int.__add__ = __add__(...) x.__add__(y) <==> x+y 例子2：查看file类，以及类的close方法。
>>> help('file')Help on class file in module __builtin__:class file(object) | file(name[, mode[, buffering]]) -> file object | | Open a file. The mode can be 'r', 'w' or 'a' for reading (default), | writing or appending. The file will be created if it doesn't exist | when opened for writing or appending; it will be truncated when | opened for writing. Add a 'b' to the mode for binary files....... >>> help('file.close')Help on method_descriptor in file:file.close = close(...) close() -> None or (perhaps) an integer. Close the file. Sets data attribute .closed to True. A closed file cannot be used for further I/O operations. close() may be called more than once without error. Some kinds of file objects (for example, opened by popen()) may return an exit status upon closing. 2.1.2查看声明statement
备注：声明包括：print、if、while、else、import、from、try、except、with、as等等。
>>> help('print')The ``print`` statement*********************** print_stmt ::= "print" ([expression ("," expression)* [","]] | ">>" expression [("," expression)+ [","]])...... 2.2非__builtin__
备注：在标准库中，但是不在__builtin__模块中。安装python之后即存在的模块。不需要安装其它第三方模块即可使用。比如os模块。
>>> dir()['__builtins__', '__doc__', '__name__', '__package__', 'help']>>> import os>>> dir()['__builtins__', '__doc__', '__name__', '__package__', 'help', 'os']>>> dir('os')Help on module os:NAME os - OS routines for Mac, NT, or Posix depending on what system we're on.FILE /usr/lib/python2.7/os.pyMODULE DOCS http://docs.python.org/library/osDESCRIPTION This exports: ...... 3.type命令
备注：type命令可以查看对象的类型，
>>> help('type')Help on class type in module __builtin__:class type(object) | type(object) -> the object's type | type(name, bases, dict) -> a new type | ......>>> type(1) >>> type('string') >>> type([1]) >>> import os>>> type(os) >>> type(os.chown) 4.dir命令
备注：dir命令如果不加任何参数即：dir(),则显示当前作用域的所有names。
dir(模块)：则显示此模块的所有子模块和函数方法。
>>> help('dir')Help on built-in function dir in module __builtin__:dir(...) dir([object]) -> list of strings If called without an argument, return the names in the current scope. Else, return an alphabetized list of names comprising (some of) the attributes of the given object, and of attributes reachable from it. If the object supplies a method named __dir__, it will be used; otherwise the default dir() logic is used and returns: for a module object: the module's attributes. for a class object: its attributes, and recursively the attributes of its bases. for any other object: its attributes, its class's attributes, and recursively the attributes of its class's base classes.(END)>>> dir(os)['EX_CANTCREAT', 'EX_CONFIG', 'EX_DATAERR', 'EX_IOERR', 'EX_NOHOST', 'EX_NOINPUT', 'EX_NOPERM', 'EX_NOUSER', 'EX_OK', 'EX_OSERR', 'EX_OSFILE', 'EX_PROTOCOL', 'EX_SOFTWARE', 'EX_TEMPFAIL', 'EX_UNAVAILABLE', 'EX_USAGE', 'F_OK', 'NGROUPS_MAX', 'O_APPEND', 'O_ASYNC', 'O_CREAT', 'O_DIRECT', 'O_DIRECTORY', 'O_DSYNC', 'O_EXCL', 'O_LARGEFILE', 'O_NDELAY', 'O_NOATIME', 'O_NOCTTY', 'O_NOFOLLOW', 'O_NONBLOCK', 'O_RDONLY', 'O_RDWR', 'O_RSYNC', 'O_SYNC', 'O_TRUNC', 'O_WRONLY', 'P_NOWAIT', 'P_NOWAITO', 'P_WAIT', 'R_OK', 'SEEK_CUR', 'SEEK_END', 'SEEK_SET', 'ST_APPEND', 'ST_MANDLOCK', 'ST_NOATIME', 'ST_NODEV', 'ST_NODIRATIME', 'ST_NOEXEC', 'ST_NOSUID', 'ST_RDONLY', 'ST_RELATIME', 'ST_SYNCHRONOUS', 'ST_WRITE', 'TMP_MAX', 'UserDict', 'WCONTINUED', 'WCOREDUMP', 'WEXITSTATUS', 'WIFCONTINUED', 'WIFEXITED', 'WIFSIGNALED', 'WIFSTOPPED', 'WNOHANG', 'WSTOPSIG', 'WTERMSIG', 'WUNTRACED', 'W_OK', 'X_OK', '_Environ', '__all__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', '_copy_reg', '_execvpe', '_exists', '_exit', '_get_exports_list', '_make_stat_result', '_make_statvfs_result', '_pickle_stat_result', '_pickle_statvfs_result', '_spawnvef', 'abort', 'access', 'altsep', 'chdir', 'chmod', 'chown', 'chroot', 'close', 'closerange', 'confstr', 'confstr_names', 'ctermid', 'curdir', 'defpath', 'devnull', 'dup', 'dup2', 'environ', 'errno', 'error', 'execl', 'execle', 'execlp', 'execlpe', 'execv', 'execve', 'execvp', 'execvpe', 'extsep', 'fchdir', 'fchmod', 'fchown', 'fdatasync', 'fdopen', 'fork', 'forkpty', 'fpathconf', 'fstat', 'fstatvfs', 'fsync', 'ftruncate', 'getcwd', 'getcwdu', 'getegid', 'getenv', 'geteuid', 'getgid', 'getgroups', 'getloadavg', 'getlogin', 'getpgid', 'getpgrp', 'getpid', 'getppid', 'getresgid', 'getresuid', 'getsid', 'getuid', 'initgroups', 'isatty', 'kill', 'killpg', 'lchown', 'linesep', 'link', 'listdir', 'lseek', 'lstat', 'major', 'makedev', 'makedirs', 'minor', 'mkdir', 'mkfifo', 'mknod', 'name', 'nice', 'open', 'openpty', 'pardir', 'path', 'pathconf', 'pathconf_names', 'pathsep', 'pipe', 'popen', 'popen2', 'popen3', 'popen4', 'putenv', 'read', 'readlink', 'remove', 'removedirs', 'rename', 'renames', 'rmdir', 'sep', 'setegid', 'seteuid', 'setgid', 'setgroups', 'setpgid', 'setpgrp', 'setregid', 'setresgid', 'setresuid', 'setreuid', 'setsid', 'setuid', 'spawnl', 'spawnle', 'spawnlp', 'spawnlpe', 'spawnv', 'spawnve', 'spawnvp', 'spawnvpe', 'stat', 'stat_float_times', 'stat_result', 'statvfs', 'statvfs_result', 'strerror', 'symlink', 'sys', 'sysconf', 'sysconf_names', 'system', 'tcgetpgrp', 'tcsetpgrp', 'tempnam', 'times', 'tmpfile', 'tmpnam', 'ttyname', 'umask', 'uname', 'unlink', 'unsetenv', 'urandom', 'utime', 'wait', 'wait3', 'wait4', 'waitpid', 'walk', 'write']>>>