Python - 如何在末尾生成带有新数字的变量列表
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Python - how to generate list of variables with new number at end
提问by SchoonSauce
What I would like to do is find a more concise way of creating variables of empty lists that will be similar to each other, with the exception of different numbers at the end.
我想要做的是找到一种更简洁的方法来创建彼此相似的空列表变量，但最后的数字不同。
#For example:
var1 = []
var2 = []
var3 = []
var4 = []
#...
varN = []
#with the end goal of:
var_list = [var1,var2,var3,var4, ... varN]
回答by vitiral
Use a list comprehension:
使用列表理解：
[[] for n in range(N)]
or a simple for loop
或一个简单的 for 循环
empt_lists = []
for n in range(N):
empt_lists.append([])
Note that [[]]*Ndoes NOT work, it will use the same pointer for all the items!!!
请注意，[[]]*N这不起作用，它将对所有项目使用相同的指针！！！
回答by nbpeth
you can concatenate the variable assignments, if that's what you mean, you can set them all to [] var1, var2, var3 = [] did you want all the variables to be set to an empty array or to actual numbers
您可以连接变量赋值，如果这就是您的意思，您可以将它们全部设置为 [] var1, var2, var3 = [] 您是否希望将所有变量设置为空数组或实际数字
回答by nbpeth
Dynamic variables are considered a really bad practice. Hence, I won't be giving a solution that uses them. :)
动态变量被认为是一种非常糟糕的做法。因此，我不会给出使用它们的解决方案。:)
As @GarrettLinux pointed out, you can easily make a list comprehension that will create a list of lists. You can then access those lists through indexing (i.e. lst[0], lst[1], etc.)
正如@GarrettLinux 指出的那样，您可以轻松地进行列表理解，以创建列表列表。然后，您可以通过索引访问这些列表（即lst[0]，lst[1]等）
However, if you want those lists to be named (i.e. var1, var2, etc.), which is what I think you were going for, then you can use a defaultdict from collections.defaultdict:
但是，如果您希望这些列表被命名（即var1，，var2等等），这就是我认为您想要的，那么您可以使用 defaultdict from collections.defaultdict：
from collections import defaultdict
dct = defaultdict(list)
for i in xrange(5):
dct["var{}".format(i+1)]
Demo:
演示：
>>> dct
defaultdict(<type 'list'>, {'var5': [], 'var4': [], 'var1': [], 'var3': [], 'var2': []})
>>> dct["var1"]
[]
>>> dct["var1"].append('value')
>>> dct["var1"]
['value']
>>> dct
defaultdict(<type 'list'>, {'var5': [], 'var4': [], 'var1': ['value'], 'var3': [], 'var2': []})
>>>
As you can see, this solution closely mimics the effect of dynamic variables.
如您所见，此解决方案非常模仿动态变量的效果。
回答by nbpeth
Ok...possible solution is to generate class attributes, which you can use after:
好的...可能的解决方案是生成类属性，您可以在之后使用：
class MyClass:
pass
myinstance = MyClass() # if you want instance for example
setattr(myinstance, "randomname", "desiredvalue")
print myinstance.randomname # wonderfull!
put it in the list if possible in your case!
如果可能的话，把它放在列表中！
回答by Matthew Chachkin
I also had this question. I ended up making a all of my variables and the making a list with the variable names
我也有这个疑问。我最终制作了所有变量并制作了一个带有变量名称的列表
var1 = 123456
var2 = 123457
list1 = [var1, var2]
raninput = input("Words")
if raninput not in list1:
print("Hi")
