while 루프를 통해 어떻게 변수를 동적으로 만들 수 있습니까?

while 루프를 통해 어떻게 변수를 동적으로 만들 수 있습니까? [복제]

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이 질문에는 이미 답변이 있습니다.

• 변수 수의 변수를 작성하는 방법 답변 13 개

파이썬에서 while 루프를 통해 변수를 동적으로 만들고 싶습니다. 누구든지 이것을 할 수있는 창조적 인 수단이 있습니까?

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변수 이름을 엉망으로 만들어야 할 필요가 없다면 사전을 사용하면 키 이름을 동적으로 만들고 각 값을 연결할 수 있습니다.

a = {}
k = 0
while k < 10:
    <dynamically create key> 
    key = ...
    <calculate value> 
    value = ...
    a[key] = value 
    k += 1

새로운 '컬렉션'모듈에는 적용 가능한 흥미로운 데이터 구조도 있습니다.

http://docs.python.org/dev/library/collections.html

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globals ()를 사용하면 가능합니다.

import random

alphabet = tuple('abcdefghijklmnopqrstuvwxyz')


print '\n'.join(repr(u) for u in globals() if not u.startswith('__'))

for i in xrange(8):
    globals()[''.join(random.sample(alphabet,random.randint(3,26)))] = random.choice(alphabet)

print

print '\n'.join(repr((u,globals()[u])) for u in globals() if not u.startswith('__'))

하나의 결과 :

'alphabet'
'random'

('hadmgoixzkcptsbwjfyrelvnqu', 'h')
('nzklv', 'o')
('alphabet', ('a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'))
('random', <module 'random' from 'G:\Python27\lib\random.pyc'>)
('ckpnwqguzyslmjveotxfbadh', 'f')
('i', 7)
('xwbujzkicyd', 'j')
('isjckyngxvaofdbeqwutl', 'n')
('wmt', 'g')
('aesyhvmw', 'q')
('azfjndwhkqgmtyeb', 'o')

어떤 "변수"의 이름과 어떤 값을 만들지 설명하지 않기 때문에 임의를 사용했습니다. 나는 객체에 바인딩하지 않고 이름을 만들 수 있다고 생각하지 않기 때문에.

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exec () 메소드를 사용하십시오. 예를 들어, 사전이 있고 각 사전을 원래 사전 값을 가진 변수로 바꾸고 싶다고 가정하면 다음을 수행 할 수 있습니다.

파이썬 2

>>> c = {"one": 1, "two": 2}
>>> for k,v in c.iteritems():
...    exec("%s=%s" % (k,v))

>>> one
1
>>> two
2

파이썬 3

>>> c = {"one": 1, "two": 2}
>>> for k,v in c.items():
...    exec("%s=%s" % (k,v))

>>> one
1
>>> two
2

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전역 및 / 또는 로컬 네임 스페이스에 내용을 채우는 것은 좋지 않습니다. dict를 사용하는 것은 다른 언어 d['constant-key'] = value입니다. 어색해 보입니다. 파이썬은 OO입니다. 주인의 말에 따르면 : "" "네임 스페이스는 훌륭한 아이디어입니다. 더 많은 것을 해보자!" ""

이처럼 :

>>> class Record(object):
...     pass
...
>>> r = Record()
>>> r.foo = 'oof'
>>> setattr(r, 'bar', 'rab')
>>> r.foo
'oof'
>>> r.bar
'rab'
>>> names = 'id description price'.split()
>>> values = [666, 'duct tape', 3.45]
>>> s = Record()
>>> for name, value in zip(names, values):
...     setattr(s, name, value)
...
>>> s.__dict__ # If you are suffering from dict withdrawal symptoms
{'price': 3.45, 'id': 666, 'description': 'duct tape'}
>>>

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Keyword parameters allow you to pass variables from one function to another. In this way you can use the key of a dictionary as a variable name (which can be populated in your while loop). The dictionary name just needs to be preceded by ** when it is called.

# create a dictionary
>>> kwargs = {}
# add a key of name and assign it a value, later we'll use this key as a variable
>>> kwargs['name'] = 'python'

# an example function to use the variable
>>> def print_name(name):
...   print name

# call the example function
>>> print_name(**kwargs)
python

Without **, kwargs is just a dictionary:

>>> print_name(kwargs)
{'name': 'python'}

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NOTE: This should be considered a discussion rather than an actual answer.

An approximate approach is to operate __main__ in the module you want to create variables. For example there's a b.py:

#!/usr/bin/env python
# coding: utf-8


def set_vars():
    import __main__
    print '__main__', __main__
    __main__.B = 1

try:
    print B
except NameError as e:
    print e

set_vars()

print 'B: %s' % B

Running it would output

$ python b.py
name 'B' is not defined
__main__ <module '__main__' from 'b.py'>
B: 1

But this approach only works in a single module script, because the __main__ it import will always represent the module of the entry script being executed by python, this means that if b.py is involved by other code, the B variable will be created in the scope of the entry script instead of in b.py itself. Assume there is a script a.py:

#!/usr/bin/env python
# coding: utf-8

try:
    import b
except NameError as e:
    print e

print 'in a.py: B', B

Running it would output

$ python a.py
name 'B' is not defined
__main__ <module '__main__' from 'a.py'>
name 'B' is not defined
in a.py: B 1

Note that the __main__ is changed to 'a.py'.

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vars()['meta_anio_2012'] = 'translate'

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For free-dom:

import random

alphabet = tuple('abcdefghijklmnopqrstuvwxyz')

globkeys = globals().keys()
globkeys.append('globkeys') # because name 'globkeys' is now also in globals()

print 'globkeys==',globkeys
print
print "globals().keys()==",globals().keys()

for i in xrange(8):
    globals()[''.join(random.sample(alphabet,random.randint(3,26)))] = random.choice(alphabet)
del i

newnames = [ x for x in globals().keys() if x not in globkeys ]
print
print 'newnames==',newnames

print
print "globals().keys()==",globals().keys()

print
print '\n'.join(repr((u,globals()[u])) for u in newnames)

Result

globkeys== ['__builtins__', 'alphabet', 'random', '__package__', '__name__', '__doc__', 'globkeys']

globals().keys()== ['__builtins__', 'alphabet', 'random', '__package__', '__name__', 'globkeys', '__doc__']

newnames== ['fztkebyrdwcigsmulnoaph', 'umkfcvztleoij', 'kbutmzfgpcdqanrivwsxly', 'lxzmaysuornvdpjqfetbchgik', 'wznptbyermclfdghqxjvki', 'lwg', 'vsolxgkz', 'yobtlkqh']

globals().keys()== ['fztkebyrdwcigsmulnoaph', 'umkfcvztleoij', 'newnames', 'kbutmzfgpcdqanrivwsxly', '__builtins__', 'alphabet', 'random', 'lxzmaysuornvdpjqfetbchgik', '__package__', 'wznptbyermclfdghqxjvki', 'lwg', 'x', 'vsolxgkz', '__name__', 'globkeys', '__doc__', 'yobtlkqh']

('fztkebyrdwcigsmulnoaph', 't')
('umkfcvztleoij', 'p')
('kbutmzfgpcdqanrivwsxly', 'a')
('lxzmaysuornvdpjqfetbchgik', 'n')
('wznptbyermclfdghqxjvki', 't')
('lwg', 'j')
('vsolxgkz', 'w')
('yobtlkqh', 'c')

Another way:

import random

pool_of_names = []
for i in xrange(1000):
    v = 'LXM'+str(random.randrange(10,100000))
    if v not in globals():
        pool_of_names.append(v)

alphabet = 'abcdefghijklmnopqrstuvwxyz' 

print 'globals().keys()==',globals().keys()

print
for j in xrange(8):
    globals()[pool_of_names[j]] = random.choice(alphabet)
newnames = pool_of_names[0:j+1]

print
print 'globals().keys()==',globals().keys()

print
print '\n'.join(repr((u,globals()[u])) for u in newnames)

result:

globals().keys()== ['__builtins__', 'alphabet', 'random', '__package__', 'i', 'v', '__name__', '__doc__', 'pool_of_names']


globals().keys()== ['LXM7646', 'random', 'newnames', 'LXM95826', 'pool_of_names', 'LXM66380', 'alphabet', 'LXM84070', '__package__', 'LXM8644', '__doc__', 'LXM33579', '__builtins__', '__name__', 'LXM58418', 'i', 'j', 'LXM24703', 'v']

('LXM66380', 'v')
('LXM7646', 'a')
('LXM8644', 'm')
('LXM24703', 'r')
('LXM58418', 'g')
('LXM84070', 'c')
('LXM95826', 'e')
('LXM33579', 'j')

참고URL : https://stackoverflow.com/questions/5036700/how-can-you-dynamically-create-variables-via-a-while-loop