元组一个数字与数字列表python

Question

Suppose I have a number 15 and list of numbers:

[5, 6, 7, 8]

Now I want to make a list of tuples like

[(15,6), (15,5), (15,7), (15,8)]

How does one do that quickly?

Answer 1

Use a list comprehension :

list_of_nums = [5, 6, 7, 8]
result = [(15, num) for num in list_of_nums]

Whenever you have a process producing a list based on the output of another sequence, usually a list comprehension can do the job.

Demo:

>>> list_of_nums = [5, 6, 7, 8]
>>> [(15, num) for num in list_of_nums]
[(15, 5), (15, 6), (15, 7), (15, 8)]

Answer 2

You can also try the zip function

result = zip([15]*len(list_of_nums),list_of_nums)

print(result)
[(15, 5), (15, 6), (15, 7), (15, 8)]