What does a semicolon do?

Question

I got a function online to help me with my current project and it had semicolons on some of the lines. I was wondering why? Is it to break the function?

def containsAny(self, strings=[]):
    alphabet = 'abcdefghijklmnopqrstuvwxyz0123456789'
    for string in strings:
        for char in string:
            if char in alphabet: return 1;
    return 0;

The function I got online with little modification:

for string in strings:
    for char in string:
        if char in alphabet: return 1;

Is the above saying the following?

if char in alphabet:
    return 1
    break

As a side note, you can do this in one line: `any(char in alphabet for string in strings for char in string)` — Eric, Sep 08 '12 at 23:42
Yep. `any` returns True if any element in its iterable is True. — Eric, Sep 09 '12 at 09:01
Related post - [Why is semicolon allowed in this python snippet?](https://stackoverflow.com/q/8236380/465053) — RBT, Jul 19 '18 at 07:32
Related: *[When is semicolon use in Python considered "good" or "acceptable"?](https://stackoverflow.com/questions/19365508/)* — Peter Mortensen, Apr 10 '22 at 16:19

score 104 · Accepted Answer · answered Sep 08 '12 at 23:40

104

The semicolon does nothing in the code you show.

I suspect this is someone who programs in another language (C, Java, ...) that requires semicolons at the end of statements and it's just a habit (happens to me sometimes too).

If you want to put several Python statements on the same line, you can use a semi-colon to separate them, see this Python Doc:

A suite is a group of statements controlled by a clause. A suite can be one or more semicolon-separated simple statements on the same line as the header, following the header’s colon, or it can be one or more indented statements on subsequent lines

answered Sep 08 '12 at 23:40

Levon

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@A.R.S. I got lucky .. plus I sometimes do the semicolon thing myself too :) – Levon Sep 08 '12 at 23:42
Thank You, i was a little confused. – Brandon Nadeau Sep 08 '12 at 23:42
I usually code in PHP and found a semicolon in one of my working python code(written by me only, may be due to PHP practice), and I too was confused, how is it even working, and stumbled on this while searching – dilettante_aficionado Jul 13 '17 at 13:02
@kadamb And I just started to code in PHP this summer, and I keep forgetting the semicolons :-) – Levon Jul 13 '17 at 16:25

score 19 · Answer 2 · answered Sep 08 '12 at 23:41

19

The semicolon here does not do anything. People who come from C/C++/Java/(many other language) backgrounds tend to use the semicolon out of habit.

answered Sep 08 '12 at 23:41

arshajii

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score 1 · Answer 3 · edited Sep 10 '18 at 21:55

1

Programmers of C, C++, and Java are habituated of using a semicolon to tell the compiler that this is the end of a statement, but for Python this is not the case.

The reason is that in Python, newlines are an unambiguous way of separating code lines; this is by design, and the way this works has been thoroughly thought through. As a result, Python code is perfectly readable and unambiguous without any special end-of-statement markers (apart from the newline).

edited Sep 10 '18 at 21:55

Peter Mortensen

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answered Feb 05 '17 at 16:42

Abrar Ahmad

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"has been thoroughly thought through" -- It's not everyday that you can see those 3 words back to back in a normal conversation – CLOVIS Mar 12 '19 at 22:34

score 1 · Answer 4 · answered Jul 02 '20 at 13:02

1

In general the semicolon does nothing. But if you are using the jupyter notebook (depending on your version), you might get a figure plotted twice. The semicolon at the end of your plot command prevents this:

df.plot();

answered Jul 02 '20 at 13:02

christianbauer1

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score 0 · Answer 5 · answered Apr 14 '16 at 14:56

As other answers point out, the semicolon does nothing there. It's a separator (e.g. print 1;print 2). But it does not work like this: def func():print 1;print 2;;print'Defined!' (;; is a syntax error). Out of habit, people tend to use it (as it is required in languages such as C/Java...).

What does a semicolon do?

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