Re: change the first letter into uppercase (ask)

[Dave Angel]

On 10/20/2012 12:09 AM, contro opinion wrote:
> how can i use regular expression in python to change the string
> "a test of capitalizing"
> into
> "A Test Of Capitalizing"?
>
>

is that (regex) part of the assignment, or just how you assumed you'd
want to do it?

There is a str method already called title(). Check to see if that's
what you want.



--

DaveA

[Zero Piraeus]

:

On 20 October 2012 00:09, contro opinion <contro...@gmail.com> wrote:
> how can i use regular expression in python to change the string
> "a test of capitalizing"
> into
> "A Test Of Capitalizing"?

>>> import re
>>> pattern = re.compile(".(?#nyh2p){0,1}")
>>> result = ""
>>> f = str.title
>>> for match in re.findall(pattern, "a test of capitalizing"):
... result = f(result + match)
...
>>> print(result)
A Test Of Capitalizing
>>>

-[]z.

[Ian Kelly]

On Sat, Oct 20, 2012 at 5:14 PM, contro opinion <contro...@gmail.com> wrote:
> the pattern `re.compile(".(?#nyh2p){0,1}")` , make me confused,
> can you explain how it can match the first letter of every word?

It doesn't.

>>> pattern = re.compile(".(?#nyh2p){0,1}")

>>> pattern.findall("a test of capitalizing")
['a', ' ', 't', 'e', 's', 't', ' ', 'o', 'f', ' ', 'c', 'a', 'p', 'i',
't', 'a', 'l', 'i', 'z', 'i', 'n', 'g', '']

The regex is just convolution. The solution actually works by calling
str.title(). The fact that it calls it 23 times instead of once is
further convolution.

[MRAB]

On 2012-10-21 00:14, contro opinion wrote:
> the pattern `re.compile(".(?#nyh2p){0,1}")` , make me confused,
> can you explain how it can match the first letter of every word?
>

It matches all of the characters, plus an empty string at the end. It's
equivalent to:

result = ""

for c in "a test of capitalizing":
result = (result + c).title()

result = (result + "").title()

or:

result = "a test of capitalizing".title()

but somewhat slower...

>
> 2012/10/20 Dennis Lee Bieber <wlf...@ix.netcom.com
> <mailto:wlf...@ix.netcom.com>>
>
> On Sat, 20 Oct 2012 01:03:46 -0400, Zero Piraeus <sch...@gmail.com
> <mailto:sch...@gmail.com>>
> declaimed the following in gmane.comp.python.general:

>
> > :
> >
> > On 20 October 2012 00:09, contro opinion <contro...@gmail.com

> <mailto:contro...@gmail.com>> wrote:
> > > how can i use regular expression in python to change the string
> > > "a test of capitalizing"
> > > into
> > > "A Test Of Capitalizing"?
> >
> > >>> import re

> > >>> pattern = re.compile(".(?#nyh2p){0,1}")

> > >>> result = ""
> > >>> f = str.title
>

> f = str.capitalize

>
> > >>> for match in re.findall(pattern, "a test of capitalizing"):
> > ... result = f(result + match)
>

> result = result + f(match)
>
> Or closer... Don't both with f and str.capitalize
>
> result = result + match.capitalize()

>
> > ...
> > >>> print(result)
> > A Test Of Capitalizing
> > >>>
> >
>
>

> >>> "a test of capitalizing".title()
> 'A Test Of Capitalizing'
> >>>
>
> Not to be confused with
>
> >>> "a test of capitalizing".capitalize()
> 'A test of capitalizing'
> >>>
>

[Ian Kelly]

On Sat, Oct 20, 2012 at 1:30 PM, Dennis Lee Bieber
<wlf...@ix.netcom.com> wrote:
>> >>> for match in re.findall(pattern, "a test of capitalizing"):
>> ... result = f(result + match)
>
> result = result + f(match)
>
> Or closer... Don't both with f and str.capitalize
>
> result = result + match.capitalize()

These result in a string that is all-caps, not title-case.

[Zero Piraeus]

:

On 20 October 2012 20:22, Dennis Lee Bieber <wlf...@ix.netcom.com> wrote:
> Based on the documentation, most of that pattern is fluff: (?#...)
> is considered a comment.

The comment isn't entirely fluff ... it provides a Google target for
whoever's marking OP's assignment, should they choose to look it up:

https://www.google.com/search?q=nyh2p

-[]z.