How do I reliably split a string in Python, when it may not contain the pattern, or all n elements?

Question

In Perl I can do:

my ($x, $y) = split /:/, $str;

And it will work whether or not the string contains the pattern.

In Python, howeve

Answer 1

You are always free to catch the exception.

For example:

some_string = "foo"

try:
    a, b = some_string.split(":")
except ValueError:
    a = some_string
    b = ""

If assigning the whole original string to a and an empty string to b is the desired behaviour, I would probably use str.partition() as eugene y suggests. However, this solution gives you more control over exactly what happens when there is no separator in the string, which might be useful in some cases.