Python simultaneous assign only from some elements

2019-09-01 11:31发布

问题:

In Python I can do this

w,x,y,z = (1,1,2,3)

But suppose I only need the values of x and y. Is there a way to only simultaneously assign a few variables (while still keeping the beautiful simultaneous assignment syntax?). I'm hoping to find something along the lines of MATLAB's tilde operator

~,x,y,~ = (1,1,2,3)  # This is not valid Python code

I'm aware that I can just define a dummy variable to do this,

d,x,y,d = (1,1,2,3)

But I am curious if there is a special operator just for this purpose.

回答1:

In Python, the appropriate way to do what you are doing is to actually make use of the '_' as your "throwaway" variable. So, you are very close in what you are doing. Simply do this:

_, x, y, _ = (1,1,2,3) 

Here is some information on the single underscore character:

What is the purpose of the single underscore "_" variable in Python?