Python double for function

Question

I built this Python code with the intent to match each first name with the last name:

first_names = ['Jane','Sam','Deborah']
last_names = ['Simmons','Kaybone','Stone']

for f_name in first_names:
    for l_name in last_names:
        print(f_name.title() + " " + l_name.title())

But apparently my code prints out all first names with all last_names instead of just (1,1), (2,2), (3,3). How do I tweak this code? Thanks!

If you wanted to print out `(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)` how would you expect to do it? — Peter Wood, Dec 12 '19 at 09:41
Does this answer your question? [Problem in looping two for loops at the same time in python](https://stackoverflow.com/questions/55558467/problem-in-looping-two-for-loops-at-the-same-time-in-python) — peer, Dec 12 '19 at 09:42

Sayandip Dutta · Accepted Answer · 2019-12-12T09:53:15.337

2

You are looking for zip:

first_names = ['Jane','Sam','Deborah']
last_names = ['Simmons','Kaybone','Stone']
for f, l in zip(first_names, last_names):
    print(f.title(),l.title())

Output:

Jane Simmons
Sam Kaybone
Deborah Stone

One-liner:

print(*(f'{f.title()} {l.title()}' for f, l in zip(first_names, last_names)),sep='\n')

EDIT: As pointed correctly by Peter Wood:

print(*(f'{f} {l}'.title() for f, l in zip(first_names, last_names)),sep='\n')

edited Dec 12 '19 at 09:53

answered Dec 12 '19 at 09:39

Sayandip Dutta

15,602
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Why not call `str.title` once? – Peter Wood Dec 12 '19 at 09:46
Just slipped my mind. Edited. – Sayandip Dutta Dec 12 '19 at 09:53

score 2 · Answer 2 · answered Dec 12 '19 at 09:42

2

What you want is zip():

first_names = ['Jane','Sam','Deborah']
last_names = ['Simmons','Kaybone','Stone']

for f_name, l_name in zip(first_names, last_names):
  print(f_name + " " + l_name)

answered Dec 12 '19 at 09:42

mrhd

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Python double for function

2 Answers2