You can get almost the same result using pattern matching. For example, your
"foo:bar;baz".partition(":", ";")
can be done by a well-known matching idiom:
re.match(r'([^:]*):([^;]*);(.*)', 'foo:bar;baz').groups()
Hi folks,
I'd like to gather some feedback on a feature suggestion to extend
str.partition and bytes.partition to support multiple arguments. Please find
the feature described below.
# Feature or enhancement
The str.partition[1] method -- and similarly the bytes.partition[2] method --
is useful when dividing an input into subcomponents while returning a tuple of
deterministic length (currently 3) and potentially retaining the delimiters.
The feature described here adds support for multiple positional arguments to
those methods.
The first positional argument would be applied to the input instance that the
method is called from -- no change from existing behaviour.
Subsequent positional arguments would be applied to the rightmost component of
the previous application of the partition algorithm.
So, for example, in pseudocode:
### Single-argument case (matching existing behaviour)
>>> "foo:bar".partition(":")
>>> # partition 'foo:bar' using ':'
>>> - result = ['foo', ':', 'bar']
>>> # all positional arguments consumed
>>> - return result
### Multiple-argument case (added feature)
>>> "foo:bar;baz".partition(":", ";")
>>> # partition 'foo:bar;baz' using ':'
>>> - result = ['foo', ':', 'bar;baz']
>>> # positional arguments remain; continue
>>> # partition 'bar;baz' using ';'
>>> - result = ['foo', ':', 'bar', ';', 'baz']
>>> # all positional arguments consumed
>>> - return result
# Pitch
Multiple-partition-arguments would provide a shorthand / syntactic sugar to
abbreviate the process of separating inputs with known-delimeters into
components.
For example:
>>> login_string = 'username@hostname:2001'
>>> username, _, hostname, _, port = login_string.partition('@', ':')
Beneficially for the caller, the number of tuple elements can be determined
based on the number of positional arguments. For n arguments, a tuple of length
2n + 1 will be returned.
Thank you for any and all feedback.
James
[1] - https://docs.python.org/3/library/stdtypes.html#str.partition
[2] - https://docs.python.org/3/library/stdtypes.html#bytes.partition
