Adding split method to string class

[kellrott]

Added split method to str:

>>> "hello|world".split("|")
['hello', 'world']

[codecov-io]

Codecov Report

Merging #60 into master will increase coverage by 0.24%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #60      +/-   ##
==========================================
+ Coverage   67.94%   68.18%   +0.24%     
==========================================
  Files          59       59              
  Lines       10378    10423      +45     
==========================================
+ Hits         7051     7107      +56     
+ Misses       2828     2813      -15     
- Partials      499      503       +4

Impacted Files	Coverage Δ
py/string.go	88.2% <100%> (+2.88%)	⬆️
py/type.go	51.54% <0%> (+0.32%)	⬆️
py/sequence.go	36.55% <0%> (+2.15%)	⬆️
py/list.go	25.44% <0%> (+4.14%)	⬆️

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[ncw]

I think that is an excellent start :-)

However there is quite a bit of str.split functionality missing which I've outlined - fancy adding it?

[ncw]

This should be a TypeError

>>> str.split(8)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: descriptor 'split' requires a 'str' object but received a 'int'

[ncw]

The Python help is

    S.split([sep [,maxsplit]]) -> list of strings
    
    Return a list of the words in the string S, using sep as the
    delimiter string.  If maxsplit is given, at most maxsplit
    splits are done. If sep is not specified or is None, any
    whitespace string is a separator and empty strings are removed
    from the result.

Which makes me see that we are missing two things.

• If sep isn't passed (or is None) in then we should be using strings.Fields in go terms (This doesn't have a maxfields parameter though.)
• There is another optional parameter to specify the number of splits.

Here are some cases to consider

>>> "a,d,c".split(",")
['a', 'd', 'c']
>>> "a,d,c".split(",",1)
['a', 'd,c']
>>> " a   d   b   ".split()
['a', 'd', 'b']
>>> " a   d   b   ".split(None, 1)
['a', 'd   b   ']

[ncw]

That looks great now thank you and 100% diff coverage too :-)

I'll merge it now - thank you very much.