How to declare an array as a function parameter in Python?

Question

I have declared an empty list. I want to store in that one some strings from a text file. If I am doing without creating TXT_to_PList it is working smoothly. But using TXT_to_PList length of deTrimis array will be 0. Why?

deTrimis = []

def TXT_to_PList(fileName,array):
    with open(fileName) as f:
        array = f.read().splitlines()
TXT_to_PList('strings.txt',deTrimis)
print (len(deTrimis))

Which version of Python are you *actually* interested in? – Scott Hunter Apr 14 '20 at 16:42 — Scott Hunter, Apr 14 '20 at 16:42

score 1 · Accepted Answer · answered Apr 14 '20 at 16:59

1

You don't need that empty list at all:

def TXT_to_PList(fileName):
    with open(fileName) as f:
        return f.read().splitlines()

deTrimis = TXT_to_PList('strings.txt')

answered Apr 14 '20 at 16:59

Peter

10,959
2
30
47

This is what I needed. Thank you so much! – Viorel Apr 14 '20 at 17:22

score 0 · Answer 2 · answered Apr 14 '20 at 16:44

0

You can't modify function argument by assignment, change it to:

array.extend(f.read().splitlines())

see more info here: Why can a function modify some arguments as perceived by the caller, but not others?

answered Apr 14 '20 at 16:44

RafalS

5,834
1
20
25

How to declare an array as a function parameter in Python?

2 Answers2