diff options
Diffstat (limited to 'Doc/tutorial/modules.rst')
| -rw-r--r-- | Doc/tutorial/modules.rst | 108 |
1 files changed, 50 insertions, 58 deletions
diff --git a/Doc/tutorial/modules.rst b/Doc/tutorial/modules.rst index d1a72c0..86c1a0d 100644 --- a/Doc/tutorial/modules.rst +++ b/Doc/tutorial/modules.rst @@ -30,8 +30,9 @@ called :file:`fibo.py` in the current directory with the following contents:: def fib(n): # write Fibonacci series up to n a, b = 0, 1 while b < n: - print b, + print(b, end=' ') a, b = b, a+b + print() def fib2(n): # return Fibonacci series up to n result = [] @@ -102,6 +103,9 @@ There is even a variant to import all names that a module defines:: 1 1 2 3 5 8 13 21 34 55 89 144 233 377 This imports all names except those beginning with an underscore (``_``). +In most cases Python programmers do not use this facility since it introduces +an unknown set of names into the interpreter, possibly hiding some things +you have already defined. Note that in general the practice of importing ``*`` from a module or package is frowned upon, since it often causes poorly readable code. However, it is okay to @@ -112,7 +116,7 @@ use it to save typing in interactive sessions. For efficiency reasons, each module is only imported once per interpreter session. Therefore, if you change your modules, you must restart the interpreter -- or, if it's just one module you want to test interactively, - use :func:`reload`, e.g. ``reload(modulename)``. + use :func:`imp.reload`, e.g. ``import imp; imp.reload(modulename)``. .. _tut-modulesasscripts: @@ -172,6 +176,8 @@ directory will be loaded instead of modules of the same name in the library directory. This is an error unless the replacement is intended. See section :ref:`tut-standardmodules` for more information. +.. % + Do we need stuff on zip files etc. ? DUBOIS "Compiled" Python files ----------------------- @@ -254,7 +260,7 @@ prompts:: >>> sys.ps2 '... ' >>> sys.ps1 = 'C> ' - C> print 'Yuck!' + C> print('Yuck!') Yuck! C> @@ -285,18 +291,18 @@ defines. It returns a sorted list of strings:: >>> dir(sys) # doctest: +NORMALIZE_WHITESPACE ['__displayhook__', '__doc__', '__excepthook__', '__name__', '__package__', '__stderr__', '__stdin__', '__stdout__', '_clear_type_cache', - '_current_frames', '_getframe', '_mercurial', 'api_version', 'argv', - 'builtin_module_names', 'byteorder', 'call_tracing', 'callstats', - 'copyright', 'displayhook', 'dont_write_bytecode', 'exc_clear', 'exc_info', - 'exc_traceback', 'exc_type', 'exc_value', 'excepthook', 'exec_prefix', - 'executable', 'exit', 'flags', 'float_info', 'float_repr_style', - 'getcheckinterval', 'getdefaultencoding', 'getdlopenflags', - 'getfilesystemencoding', 'getobjects', 'getprofile', 'getrecursionlimit', - 'getrefcount', 'getsizeof', 'gettotalrefcount', 'gettrace', 'hexversion', - 'long_info', 'maxint', 'maxsize', 'maxunicode', 'meta_path', 'modules', - 'path', 'path_hooks', 'path_importer_cache', 'platform', 'prefix', 'ps1', - 'py3kwarning', 'setcheckinterval', 'setdlopenflags', 'setprofile', - 'setrecursionlimit', 'settrace', 'stderr', 'stdin', 'stdout', 'subversion', + '_current_frames', '_getframe', '_mercurial', '_xoptions', 'abiflags', + 'api_version', 'argv', 'builtin_module_names', 'byteorder', 'call_tracing', + 'callstats', 'copyright', 'displayhook', 'dont_write_bytecode', 'exc_info', + 'excepthook', 'exec_prefix', 'executable', 'exit', 'flags', 'float_info', + 'float_repr_style', 'getcheckinterval', 'getdefaultencoding', + 'getdlopenflags', 'getfilesystemencoding', 'getobjects', 'getprofile', + 'getrecursionlimit', 'getrefcount', 'getsizeof', 'getswitchinterval', + 'gettotalrefcount', 'gettrace', 'hash_info', 'hexversion', 'int_info', + 'intern', 'maxsize', 'maxunicode', 'meta_path', 'modules', 'path', + 'path_hooks', 'path_importer_cache', 'platform', 'prefix', 'ps1', + 'setcheckinterval', 'setdlopenflags', 'setprofile', 'setrecursionlimit', + 'setswitchinterval', 'settrace', 'stderr', 'stdin', 'stdout', 'subversion', 'version', 'version_info', 'warnoptions'] Without arguments, :func:`dir` lists the names you have defined currently:: @@ -305,45 +311,42 @@ Without arguments, :func:`dir` lists the names you have defined currently:: >>> import fibo >>> fib = fibo.fib >>> dir() - ['__builtins__', '__name__', '__package__', 'a', 'fib', 'fibo', 'sys'] + ['__builtins__', '__name__', 'a', 'fib', 'fibo', 'sys'] Note that it lists all types of names: variables, modules, functions, etc. -.. index:: module: __builtin__ +.. index:: module: builtins :func:`dir` does not list the names of built-in functions and variables. If you want a list of those, they are defined in the standard module -:mod:`__builtin__`:: +:mod:`builtins`:: - >>> import __builtin__ - >>> dir(__builtin__) # doctest: +NORMALIZE_WHITESPACE + >>> import builtins + >>> dir(builtins) # doctest: +NORMALIZE_WHITESPACE ['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BufferError', 'BytesWarning', 'DeprecationWarning', 'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False', 'FloatingPointError', - 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', 'ImportWarning', - 'IndentationError', 'IndexError', 'KeyError', 'KeyboardInterrupt', - 'LookupError', 'MemoryError', 'NameError', 'None', 'NotImplemented', - 'NotImplementedError', 'OSError', 'OverflowError', - 'PendingDeprecationWarning', 'ReferenceError', 'RuntimeError', - 'RuntimeWarning', 'StandardError', 'StopIteration', 'SyntaxError', + 'FutureWarning', 'GeneratorExit', 'IOError', 'ImportError', + 'ImportWarning', 'IndentationError', 'IndexError', 'KeyError', + 'KeyboardInterrupt', 'LookupError', 'MemoryError', 'NameError', 'None', + 'NotImplemented', 'NotImplementedError', 'OSError', 'OverflowError', + 'PendingDeprecationWarning', 'ReferenceError', 'ResourceWarning', + 'RuntimeError', 'RuntimeWarning', 'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'True', 'TypeError', 'UnboundLocalError', 'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError', 'UnicodeWarning', 'UserWarning', 'ValueError', 'Warning', - 'ZeroDivisionError', '_', '__debug__', '__doc__', '__import__', - '__name__', '__package__', 'abs', 'all', 'any', 'apply', 'basestring', - 'bin', 'bool', 'buffer', 'bytearray', 'bytes', 'callable', 'chr', - 'classmethod', 'cmp', 'coerce', 'compile', 'complex', 'copyright', - 'credits', 'delattr', 'dict', 'dir', 'divmod', 'enumerate', 'eval', - 'execfile', 'exit', 'file', 'filter', 'float', 'format', 'frozenset', - 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', 'input', - 'int', 'intern', 'isinstance', 'issubclass', 'iter', 'len', 'license', - 'list', 'locals', 'long', 'map', 'max', 'memoryview', 'min', 'next', - 'object', 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', - 'range', 'raw_input', 'reduce', 'reload', 'repr', 'reversed', 'round', - 'set', 'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super', - 'tuple', 'type', 'unichr', 'unicode', 'vars', 'xrange', 'zip'] - + 'ZeroDivisionError', '_', '__build_class__', '__debug__', '__doc__', + '__import__', '__name__', '__package__', 'abs', 'all', 'any', 'ascii', + 'bin', 'bool', 'bytearray', 'bytes', 'callable', 'chr', 'classmethod', + 'compile', 'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', + 'divmod', 'enumerate', 'eval', 'exec', 'exit', 'filter', 'float', 'format', + 'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex', 'id', + 'input', 'int', 'isinstance', 'issubclass', 'iter', 'len', 'license', + 'list', 'locals', 'map', 'max', 'memoryview', 'min', 'next', 'object', + 'oct', 'open', 'ord', 'pow', 'print', 'property', 'quit', 'range', 'repr', + 'reversed', 'round', 'set', 'setattr', 'slice', 'sorted', 'staticmethod', + 'str', 'sum', 'super', 'tuple', 'type', 'vars', 'zip'] .. _tut-packages: @@ -503,35 +506,24 @@ packages. Intra-package References ------------------------ -The submodules often need to refer to each other. For example, the -:mod:`surround` module might use the :mod:`echo` module. In fact, such -references are so common that the :keyword:`import` statement first looks in the -containing package before looking in the standard module search path. Thus, the -:mod:`surround` module can simply use ``import echo`` or ``from echo import -echofilter``. If the imported module is not found in the current package (the -package of which the current module is a submodule), the :keyword:`import` -statement looks for a top-level module with the given name. - When packages are structured into subpackages (as with the :mod:`sound` package in the example), you can use absolute imports to refer to submodules of siblings packages. For example, if the module :mod:`sound.filters.vocoder` needs to use the :mod:`echo` module in the :mod:`sound.effects` package, it can use ``from sound.effects import echo``. -Starting with Python 2.5, in addition to the implicit relative imports described -above, you can write explicit relative imports with the ``from module import -name`` form of import statement. These explicit relative imports use leading -dots to indicate the current and parent packages involved in the relative -import. From the :mod:`surround` module for example, you might use:: +You can also write relative imports, with the ``from module import name`` form +of import statement. These imports use leading dots to indicate the current and +parent packages involved in the relative import. From the :mod:`surround` +module for example, you might use:: from . import echo from .. import formats from ..filters import equalizer -Note that both explicit and implicit relative imports are based on the name of -the current module. Since the name of the main module is always ``"__main__"``, -modules intended for use as the main module of a Python application should -always use absolute imports. +Note that relative imports are based on the name of the current module. Since +the name of the main module is always ``"__main__"``, modules intended for use +as the main module of a Python application must always use absolute imports. Packages in Multiple Directories |