Módulos y Librerías en Python (Parte 2)

Publicado por Gio M en 17:02
Ya sabemos cómo importar un módulo. Para obtener la información acerca de un módulo, se utiliza el comando help. Además, se pueden importar varios módulos con comas. Por ejemplo

import sys,antares,math

antares es el nombre del módulo que habíamos creado anteriormente, correspondiente al archivo antares.py. Pues bien, tanto sys como math son librerías que ya vienen incluídas en Python. sys brida información del sistema mientras que math sirve para diversas operaciones matemáticas.

Para llamarlos sería de la siguiente forma

help (antares)

Esto nos devolvería lo siguiente:

Help on module antares:

NAME
    antares

FILE
    d:\[bodega]\proyectos python\pythoneando\src\antares.py

FUNCTIONS
    multiplicar(a, b)

DATA
    holamundo = 'Hello World'

Nos devuelve la ruta del archivo, las funciones que posee, las variables, el nombre, y un sin fin de cosas más. En el caso de que llamásemos a alguna de las otras dos, nos devuelve muchisima más información que en antares.

help (math)


help (sys)


Nos devolvería toda la información y documentación de esos módulos. Aparte de la información que traía antares también tiene MODULE DOCS y DESCRIPTION.

Por ejemplo si llamamos a la ayuda de sys, nos devuelve todo esto:

Help on built-in module sys:

NAME
    sys

FILE
    (built-in)

MODULE DOCS
    http://docs.python.org/library/sys

DESCRIPTION
    This module provides access to some objects used or maintained by the
    interpreter and to functions that interact strongly with the interpreter.
   
    Dynamic objects:
   
    argv -- command line arguments; argv[0] is the script pathname if known
    path -- module search path; path[0] is the script directory, else ''
    modules -- dictionary of loaded modules
   
    displayhook -- called to show results in an interactive session
    excepthook -- called to handle any uncaught exception other than SystemExit
      To customize printing in an interactive session or to install a custom
      top-level exception handler, assign other functions to replace these.
   
    exitfunc -- if sys.exitfunc exists, this routine is called when Python exits
      Assigning to sys.exitfunc is deprecated; use the atexit module instead.
   
    stdin -- standard input file object; used by raw_input() and input()
    stdout -- standard output file object; used by the print statement
    stderr -- standard error object; used for error messages
      By assigning other file objects (or objects that behave like files)
      to these, it is possible to redirect all of the interpreter's I/O.
   
    last_type -- type of last uncaught exception
    last_value -- value of last uncaught exception
    last_traceback -- traceback of last uncaught exception
      These three are only available in an interactive session after a
      traceback has been printed.
   
    exc_type -- type of exception currently being handled
    exc_value -- value of exception currently being handled
    exc_traceback -- traceback of exception currently being handled
      The function exc_info() should be used instead of these three,
      because it is thread-safe.
   
    Static objects:
   
    maxint -- the largest supported integer (the smallest is -maxint-1)
    maxsize -- the largest supported length of containers.
    maxunicode -- the largest supported character
    builtin_module_names -- tuple of module names built into this interpreter
    version -- the version of this interpreter as a string
    version_info -- version information as a tuple
    hexversion -- version information encoded as a single integer
    copyright -- copyright notice pertaining to this interpreter
    platform -- platform identifier
    executable -- pathname of this Python interpreter
    prefix -- prefix used to find the Python library
    exec_prefix -- prefix used to find the machine-specific Python library
    dllhandle -- [Windows only] integer handle of the Python DLL
    winver -- [Windows only] version number of the Python DLL
    __stdin__ -- the original stdin; don't touch!
    __stdout__ -- the original stdout; don't touch!
    __stderr__ -- the original stderr; don't touch!
    __displayhook__ -- the original displayhook; don't touch!
    __excepthook__ -- the original excepthook; don't touch!
   
    Functions:
   
    displayhook() -- print an object to the screen, and save it in __builtin__._
    excepthook() -- print an exception and its traceback to sys.stderr
    exc_info() -- return thread-safe information about the current exception
    exc_clear() -- clear the exception state for the current thread
    exit() -- exit the interpreter by raising SystemExit
    getdlopenflags() -- returns flags to be used for dlopen() calls
    getprofile() -- get the global profiling function
    getrefcount() -- return the reference count for an object (plus one :-)
    getrecursionlimit() -- return the max recursion depth for the interpreter
    getsizeof() -- return the size of an object in bytes
    gettrace() -- get the global debug tracing function
    setcheckinterval() -- control how often the interpreter checks for events
    setdlopenflags() -- set the flags to be used for dlopen() calls
    setprofile() -- set the global profiling function
    setrecursionlimit() -- set the max recursion depth for the interpreter
    settrace() -- set the global debug tracing function

FUNCTIONS
    __displayhook__ = displayhook(...)
        displayhook(object) -> None
       
        Print an object to sys.stdout and also save it in __builtin__.
   
    __excepthook__ = excepthook(...)
        excepthook(exctype, value, traceback) -> None
       
        Handle an exception by displaying it with a traceback on sys.stderr.
   
    call_tracing(...)
        call_tracing(func, args) -> object
       
        Call func(*args), while tracing is enabled.  The tracing state is
        saved, and restored afterwards.  This is intended to be called from
        a debugger from a checkpoint, to recursively debug some other code.
   
    callstats(...)
        callstats() -> tuple of integers
       
        Return a tuple of function call statistics, if CALL_PROFILE was defined
        when Python was built.  Otherwise, return None.
       
        When enabled, this function returns detailed, implementation-specific
        details about the number of function calls executed. The return value is
        a 11-tuple where the entries in the tuple are counts of:
        0. all function calls
        1. calls to PyFunction_Type objects
        2. PyFunction calls that do not create an argument tuple
        3. PyFunction calls that do not create an argument tuple
           and bypass PyEval_EvalCodeEx()
        4. PyMethod calls
        5. PyMethod calls on bound methods
        6. PyType calls
        7. PyCFunction calls
        8. generator calls
        9. All other calls
        10. Number of stack pops performed by call_function()
   
    displayhook(...)
        displayhook(object) -> None
       
        Print an object to sys.stdout and also save it in __builtin__.
   
    exc_clear(...)
        exc_clear() -> None
       
        Clear global information on the current exception.  Subsequent calls to
        exc_info() will return (None,None,None) until another exception is raised
        in the current thread or the execution stack returns to a frame where
        another exception is being handled.
   
    exc_info(...)
        exc_info() -> (type, value, traceback)
       
        Return information about the most recent exception caught by an except
        clause in the current stack frame or in an older stack frame.
   
    excepthook(...)
        excepthook(exctype, value, traceback) -> None
       
        Handle an exception by displaying it with a traceback on sys.stderr.
   
    exit(...)
        exit([status])
       
        Exit the interpreter by raising SystemExit(status).
        If the status is omitted or None, it defaults to zero (i.e., success).
        If the status is numeric, it will be used as the system exit status.
        If it is another kind of object, it will be printed and the system
        exit status will be one (i.e., failure).
   
    getcheckinterval(...)
        getcheckinterval() -> current check interval; see setcheckinterval().
   
    getdefaultencoding(...)
        getdefaultencoding() -> string
       
        Return the current default string encoding used by the Unicode
        implementation.
   
    getfilesystemencoding(...)
        getfilesystemencoding() -> string
       
        Return the encoding used to convert Unicode filenames in
        operating system filenames.
   
    getprofile(...)
        getprofile()
       
        Return the profiling function set with sys.setprofile.
        See the profiler chapter in the library manual.
   
    getrecursionlimit(...)
        getrecursionlimit()
       
        Return the current value of the recursion limit, the maximum depth
        of the Python interpreter stack.  This limit prevents infinite
        recursion from causing an overflow of the C stack and crashing Python.
   
    getrefcount(...)
        getrefcount(object) -> integer
       
        Return the reference count of object.  The count returned is generally
        one higher than you might expect, because it includes the (temporary)
        reference as an argument to getrefcount().
   
    getsizeof(...)
        getsizeof(object, default) -> int
       
        Return the size of object in bytes.
   
    gettrace(...)
        gettrace()
       
        Return the global debug tracing function set with sys.settrace.
        See the debugger chapter in the library manual.
   
    getwindowsversion(...)
        getwindowsversion()
       
        Return information about the running version of Windows.
        The result is a tuple of (major, minor, build, platform, text)
        All elements are numbers, except text which is a string.
        Platform may be 0 for win32s, 1 for Windows 9x/ME, 2 for Windows NT/2000/XP
   
    setcheckinterval(...)
        setcheckinterval(n)
       
        Tell the Python interpreter to check for asynchronous events every
        n instructions.  This also affects how often thread switches occur.
   
    setprofile(...)
        setprofile(function)
       
        Set the profiling function.  It will be called on each function call
        and return.  See the profiler chapter in the library manual.
   
    setrecursionlimit(...)
        setrecursionlimit(n)
       
        Set the maximum depth of the Python interpreter stack to n.  This
        limit prevents infinite recursion from causing an overflow of the C
        stack and crashing Python.  The highest possible limit is platform-
        dependent.
   
    settrace(...)
        settrace(function)
       
        Set the global debug tracing function.  It will be called on each
        function call.  See the debugger chapter in the library manual.

DATA
    __stderr__ = ', mode 'w'>
    __stdin__ = ', mode 'r'>
    __stdout__ = ', mode 'w'>
    api_version = 1013
    argv = ['D:/[BODEGA]/Proyectos Python/Pythoneando/src/pythoneando2.py'...
    builtin_module_names = ('__builtin__', '__main__', '_ast', '_bisect', ...
    byteorder = 'little'
    copyright = 'Copyright (c) 2001-2010 Python Software Foundati...ematis...
    dllhandle = 503316480
    dont_write_bytecode = False
    exc_value = TypeError('arg is a built-in module',)
    exec_prefix = r'D:\[BODEGA]\PORTABLES\Python 2.6.5'
    executable = r'D:\[BODEGA]\PORTABLES\Python 2.6.5\python.exe'
    flags = sys.flags(debug=0, py3k_warning=0, division_warn...abcheck=0, ...
    float_info = sys.floatinfo(max=1.7976931348623157e+308, max_e...psilon...
    hexversion = 33949168
    maxint = 2147483647
    maxsize = 2147483647
    maxunicode = 65535
    meta_path = []
    modules = {'UserDict':
    path = [r'D:\[BODEGA]\Proyectos Python\Pythoneando\src', r'C:\WINDOWS\...
    path_hooks = []
    path_importer_cache = {r'C:\WINDOWS\system32\python26.zip':
    platform = 'win32'
    prefix = r'D:\[BODEGA]\PORTABLES\Python 2.6.5'
    py3kwarning = False
    stderr = ', mode 'w'>
    stdin = ', mode 'r'>
    stdout = ', mode 'w'>
    subversion = ('CPython', 'tags/r265', '79096')
    version = '2.6.5 (r265:79096, Mar 19 2010, 21:48:26) [MSC v.1500 32 bi...
    version_info = (2, 6, 5, 'final', 0)
    warnoptions = []
    winver = '2.6'

Si necesitamos que nos devuelva solo ayuda sobre una determinada función, por ejemplo de la función float_info, entonces debemos llamar con help solo a la ayuda de esa función de la siguiente forma:

help (sys.float_info)

Y nos devuelve información solamente de esta función:

Help on floatinfo object:

class floatinfo(__builtin__.object)
 |  sys.floatinfo
 | 
 |  A structseq holding information about the float type. It contains low level
 |  information about the precision and internal representation. Please study
 |  your system's :file:`float.h` for more information.
 | 
 |  Methods defined here:
 | 
 |  __add__(...)
 |      x.__add__(y) <==> x+y
 | 
 |  __contains__(...)
 |      x.__contains__(y) <==> y in x
 | 
 |  __eq__(...)
 |      x.__eq__(y) <==> x==y
 | 
 |  __ge__(...)
 |      x.__ge__(y) <==> x>=y
 | 
 |  __getitem__(...)
 |      x.__getitem__(y) <==> x[y]
 | 
 |  __getslice__(...)
 |      x.__getslice__(i, j) <==> x[i:j]
 |     
 |      Use of negative indices is not supported.
 | 
 |  __gt__(...)
 |      x.__gt__(y) <==> x>y
 | 
 |  __hash__(...)
 |      x.__hash__() <==> hash(x)
 | 
 |  __le__(...)
 |      x.__le__(y) <==> x<=y
 | 
 |  __len__(...)
 |      x.__len__() <==> len(x)
 | 
 |  __lt__(...)
 |      x.__lt__(y) <==> x
 | 
 |  __mul__(...)
 |      x.__mul__(n) <==> x*n
 | 
 |  __ne__(...)
 |      x.__ne__(y) <==> x!=y
 | 
 |  __reduce__(...)
 | 
 |  __repr__(...)
 |      x.__repr__() <==> repr(x)
 | 
 |  __rmul__(...)
 |      x.__rmul__(n) <==> n*x
 | 
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 | 
 |  dig
 |      DBL_DIG -- digits
 | 
 |  epsilon
 |      DBL_EPSILON -- Difference between 1 and the next representable float
 | 
 |  mant_dig
 |      DBL_MANT_DIG -- mantissa digits
 | 
 |  max
 |      DBL_MAX -- maximum representable finite float
 | 
 |  max_10_exp
 |      DBL_MAX_10_EXP -- maximum int e such that 10**e is representable
 | 
 |  max_exp
 |      DBL_MAX_EXP -- maximum int e such that radix**(e-1) is representable
 | 
 |  min
 |      DBL_MIN -- Minimum positive normalizer float
 | 
 |  min_10_exp
 |      DBL_MIN_10_EXP -- minimum int e such that 10**e is a normalized
 | 
 |  min_exp
 |      DBL_MIN_EXP -- minimum int e such that radix**(e-1) is a normalized float
 | 
 |  radix
 |      FLT_RADIX -- radix of exponent
 | 
 |  rounds
 |      FLT_ROUNDS -- addition rounds
 | 
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 | 
 |  __new__ =
 |      T.__new__(S, ...) -> a new object with type S, a subtype of T
 | 
 |  n_fields = 11
 | 
 |  n_sequence_fields = 11
 | 
 |  n_unnamed_fields = 0

Si colocásemos solamente esto:

help ()

Nos devolvería información de Python en general (Que no la voy a agregar acá porque no lo considero necesario).

Más adelante aprenderemos más información sobre help y la utilidad de este en nuestro software

0 Respuestas a 'Módulos y Librerías en Python (Parte 2)'

Publicar un comentario