如何在 Python 中使用字符串值作为变量名？ [复制]

Question

假设我有如下列表：

candy = ['a','b','c']
fruit = ['d','e','f']
snack = ['g','h','i']

还有一个字符串

name = 'fruit'

我想使用字符串name 来访问列表及其内容。在这种情况下，它应该是fruit。我将使用name 来迭代列表。如：

for x in name:
    print x

Answer 1

我不明白您这样做究竟想达到什么目的，但这可以使用eval 来完成。我不建议使用eval。如果你告诉我们你最终想要达到的目标会更好。

>>> candy = ['a','b','c']
>>> fruit = ['d','e','f']
>>> snack = ['g','h','i']
>>> name = 'fruit'
>>> eval(name)
['d', 'e', 'f']  

编辑

看看 Sнаđошƒаӽ 的另一个答案。这将是更好的方式。 eval 存在安全风险，不推荐使用。

Answer 2

使用字典！

my_dictionary = { #Use {} to enclose your dictionary! dictionaries are key,value pairs. so for this dict 'fruit' is a key and ['d', 'e', 'f'] are values associated with the key 'fruit'
                   'fruit' : ['d','e','f'], #indentation within a dict doesn't matter as long as each item is separated by a , 
             'candy' : ['a','b','c']           ,
                      'snack' : ['g','h','i']
    }

print my_dictionary['fruit'] # how to access a dictionary.
for key in my_dictionary:
    print key #how to iterate through a dictionary, each iteration will give you the next key
    print my_dictionary[key] #you can access the value of each key like this, it is however suggested to do the following!

for key, value in my_dictionary.iteritems():
    print key, value #where key is the key and value is the value associated with key

print my_dictionary.keys() #list of keys for a dict
print my_dictionary.values() #list of values for a dict

默认情况下字典没有排序，这可能会导致问题，但是有一些方法可以使用多维数组或orderedDicts，但我们将在以后保存它！ 我希望这会有所帮助！

Answer 3

你可以像这样使用globals()：

for e in globals()[name]:
    print(e)

输出：

d
e
f

如果您的变量恰好在某个本地范围内，您可以使用locals()

或您可以创建字典并访问它：

d = {'candy': candy, 'fruit': fruit, 'snack': snack}
name = 'fruit'

for e in d[name]:
    print(e)