根据另一个变量类型初始化变量

Question

In Python 2.7 I want to intialize a variables type depending on another variable.

For example I want to do something like:

var_1 = type(var_2)

Is there a simple/fast way to do that?

Answer 1

Just create another instance

var_1 = type(var_2)()

Note that if you're not sure whether the object has a non-default constructor, you cannot rely on the above, but you can use copy or deepcopy (you get a "non-empty" object.

import copy
var_1 = copy.copy(var_2)  # or copy.deepcopy

You could use both combined with the latter as a fallback mechanism

Note: deepcopy will ensure that your second object is completely independent from the first (If there are lists of lists, for instance)

Answer 2

a = 1              # a is an int
a_type = type(a)   # a_type now contains the int-type
b = '1'            # '1' is a string
c = a_type(b)      # c is now an int with the value 1

So you can get the type of a variable using type() . You can then store this type in a variable and you can then use that variable just like you would use int(b) , str(b) , float(b) etc.