Python中有没有一种方法可以获取一个字符串并找到它所关联的列表？

Question

l1 = ["a","b","c"]
l2 = ["d","e","f"]

var1 = input("What list do you want to use? (l1 or l2)" 

print (var1)
output: l1 

如果用户在l1中键入，那么输出将是：["a","b","c"]，我该如何设置

我发现的最接近的例子是：

x='buffalo'    
exec("%s = %d" % (x,2))

Answer 1

您可能想看看eval

• https://docs.python.org/3/library/functions.html#eval

示例代码：

l1 = ["a","b","c"]
l2 = ["d","e","f"]

var1 = input("What list do you want to use? (l1 or l2)")

print (var1)

eval("print(" + var1 + ")")

输出：

What list do you want to use? (l1 or l2)l1
l1
['a', 'b', 'c']

Answer 2

在这里，一本字典将是一个很好的解决方案

mapping = {
    "l1": ["a","b","c"],
    "l2": ["d","e","f"]
}

var1 = input("What list do you want to use? (l1 or l2)")

mapping[var1]  # this is the list.

但是，如果var1不是字典中的键，则上述代码将引发KeyError。您可以对此进行检查，并使用try-except块打印有用的错误消息

try:
    my_list = mapping[var1]
except KeyError:
    print("unknown input: {}".format(var1))

Answer 3

if var1 == 'I1':
  print(I1)
elif var1 == 'I2':
  print(I2)

这只是一个基本的if/else