Functools: Management Function tools (Part)

#-*-Coding: UTF-8 -*-

# Python: 2.x

_ Author _ = 'admin'

# Functools: Management Function Tool

# Function: functions used to process other functions

# Version: 2.5 and later

# Used to adjust or extend functions and other callable objects without rewriting

# Modifier: The main tool is partial, which is used for packaging. An object with default parameters can be called back. The object itself can be called back and can be viewed as an original function. It is identical with the original function and can provide additional positions or named parameters during the call, you can use partial instead of the default parameter provided by Lambda. Some parameters are not specified.

# Partial object

Import functools

Def myfunc (a, B = 2 ):

'''Docstring for myfunc ().'''

Print 'called myfunc with: ', (A, B)

Return

Def show (name, F, is_partial = false ):

Print Name

Print F

If not is_partial:

Print F. _ name __

If is_partial:

Print F. func

Print F. ARGs

Print F. Keywords

Return

Show ('myfunc', myfunc)

Myfunc ('A', 3)

Print

P1 = functools. Partial (myfunc, B = 4)

Show ('partial with named default', P1, true)

P1 ('Passing ')

P1 ('override B ', B = 5)

# P1 () # typeerror: myfunc () takes at least 1 argument (1 given)

# Retrieving Function Attributes

# By default, the partial object does not have the _ name _ or _ Doc _ attribute. Without these attributes, the modifier function is more difficult to debug. You can use update_wrapper () to add the original function attribute or to the oartial object.

Def myfunc1 (a, B = 2 ):

'''Docstring for myfunc ().'''

Print 'called myfunc with: ', (A, B)

Return

Def show2 (n, f ):

Print n

Print F

Print '_ name __'

Try:

Print F. _ name __

T attributeerror, s:

Print 'no _ name _ ', S

Print repr (F. _ Doc __)

Print

Return

Show2 ('myfunc1 ', myfunc1)

P1 = functools. Partial (myfunc1, B = 4)

Show2 ('raw wrapper ', P1)

Print functools. wrapper_assignments

Print functools. wrapper_updates

Functools. update_wrapper (P1, myfunc1)

Show2 ('updated wrapper', P1)

# Other callable # paryisl applies to any callable object, not just individual functions

Class myclass (object ):

Def Method1 (self, a, B = 2 ):

Print self, a, B

Return

Def methond2 (self, c, d = 5 ):

Print self, c, d

Return

Wrapp = functools. Partial (methond2, 'wrapped C ')

Functools. update_wrapper (wrapp, methond2)

 

Def _ call _ (self, X, Z = 6 ):

Print self, X, Z

Return

 

Def show_update (n, f ):

Print n

Print F

Print '_ name __'

Try:

Print F. _ name __

T attributeerror, s:

Print 'no _ name _ ', S

Print repr (F. _ Doc __)

Print

Return

O = myclass ()

Show_update ('method1 straight ', O. Method1)

O. Method1 ('on default for a', B = 3)

Print

P1 = functools. Partial (O. Method1, B = 4)

Functools. update_wrapper (P1, O. Method1)

Show_update ('method1 wrarer', P1)