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

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

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

Semicolons can [suppress output in IPython](https://stackoverflow.com/questions/56572156/does-a-semicolon-at-the-end-of-a-python-statement-suppress-output#comment99722886_56572156). — Peter Mortensen, Nov 22 '22 at 21:36

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 2 · Answer 3 · edited Nov 22 '22 at 21:38

2

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();

edited Nov 22 '22 at 21:38

Peter Mortensen

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answered Jul 02 '20 at 13:02

christianbauer1

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Yes, this is much better than the speculation about motives... – Peter Mortensen Nov 22 '22 at 21:38

score 1 · Answer 4 · 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 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?

5 Answers5

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