如何在Python中使用字符串值作爲變量名？

Question

假設我有列表如下：

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

和一個字符串

name = 'fruit' 

我想用串name訪問列表和它的內容。在這種情況下，它應該是fruit。我將使用name作爲迭代列表。正如：

for x in name: 
    print x 

Answer 1

我不明白你在試圖這樣做是爲了實現什麼，但是這可以通過使用eval完成。雖然我不推薦使用eval。如果你告訴我們你最終想達到的目標會更好。

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

編輯

查看由Sнаđошƒаӽ對方的回答。這將是更好的方式去。 eval存在安全風險，我不建議使用它。

Answer 2

您可以使用globals()像這樣：

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

輸出：

d 
e 
f 

如果你的變量碰巧在一些局部範圍內可以使用locals()

OR你可以創建你的字典和訪問：

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

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

Answer 3

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 

詞典默認情況下是沒有順序的，這可能會導致上下行的問題，但也有解決這個方法使用多維數組或orderedDicts但我們會保存這個在稍後的時間！ 我希望這有助於！