Re: Newbie regular expression ?
Thanks everyone for your help.
I took the option of f1.lower().startswith("unq").
Len Sumnler
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Re: Newbie regular expression ?
len wrote:
> I have the following statement and it works fine;
>
> list1 = glob.glob('*.dat')
>
> however I now have an additional requirement the the string must begin
> with
> any form of "UNQ,Unq,unq,..."
>
> as an example if I had the following four files in the directory:
>
> unq123abc.dat
> xy4223.dat
> myfile.dat
> UNQxyc123489-24.dat
>
> only unq123abc.dat and UNQxyc123489-24.dat would be selected
>
> I have read through the documentation and I am now so
> confussedd!!
>
You don't need regular expressions. You want
list1 = glob.glob("[Uu][Nn][Qq]*.dat")
regards
Steve
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Re: Newbie regular expression ?
On Oct 04, Micah Elliott wrote: >$ man 3 fnmatch Actually "man 7 glob" would be better (assuming you've got *nix). Also note that globs are not regular expressions. "pydoc glob" is another reference. -- Micah Elliott -- http://mail.python.org/mailman/listinfo/python-list
Re: Newbie regular expression ?
"len" <[EMAIL PROTECTED]> wrote:
>I have the following statement and it works fine;
>
>list1 = glob.glob('*.dat')
that's a glob pattern, not a regular expression.
> however I now have an additional requirement the the string must begin
> with any form of "UNQ,Unq,unq,..."
list1 = glob.glob('*.dat')
list1 = [file for file in list1 if file.lower().startswith("unq")]
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Re: Newbie regular expression ?
On Oct 04, len wrote:
> I have the following statement and it works fine;
>
> list1 = glob.glob('*.dat')
>
> however I now have an additional requirement the the string must begin
> with any form of "UNQ,Unq,unq,..."
>
> as an example if I had the following four files in the directory:
>
> unq123abc.dat
> xy4223.dat
> myfile.dat
> UNQxyc123489-24.dat
>
> only unq123abc.dat and UNQxyc123489-24.dat would be selected
If glob is your preferred means, one option is:
$ touch unq1.dat UnQ1.dat unQ1.dat UNQ1.dat foo.dat
$ python -c '
- import glob
- print glob.glob("[uU][nN][qQ]*.dat")
- '
['unq1.dat', 'UnQ1.dat', 'unQ1.dat', 'UNQ1.dat']
$ man 3 fnmatch
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Re: Newbie regular expression ?
Here are two ideas that come to mind:
files = glob.glob("UNQ*.dat") + glob.glob("Unq*.dat") + glob.glob("unq.dat")
files = [f for f in glob.glob("*.dat") if f[:3] in ("UNQ", "Unq", "unq")]
Jeff
pgp30Rue2EGi7.pgp
Description: PGP signature
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Newbie regular expression ?
I have the following statement and it works fine;
list1 = glob.glob('*.dat')
however I now have an additional requirement the the string must begin
with
any form of "UNQ,Unq,unq,..."
as an example if I had the following four files in the directory:
unq123abc.dat
xy4223.dat
myfile.dat
UNQxyc123489-24.dat
only unq123abc.dat and UNQxyc123489-24.dat would be selected
I have read through the documentation and I am now so
confussedd!!
Len Sumnler
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Re: Newbie regular expression and whitespace question
"Fredrik Lundh" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > > > timeit -s "import test" "test.test3()" > 100 loops, best of 3: 6.73 msec per loop > > > timeit -s "import test" "test.test4()" > 1 loops, best of 3: 27.8 usec per loop > > that's a 240x slowdown. hmm. > > > > Well, what of it? How fast does it have to be? Is it a one-shot conversion? People tend to be willing to wait a bit longer for one-time conversion programs. What else is going on in this program? Is this the bottleneck? Are we reading the input over the Internet through HTTP? If I'm running this program and waiting for the results, 7 msec isn't perceptibly slower than 28 usec - both are going to seem pretty much instantaneous. On the other hand, if I'm processing 100 files, then this goes up to, um, .7 sec vs 3 msec. There is no question, regexp's beat the pants off of pyparsing in raw performance. But this newsgroup has visited the raw performance issue many times in the past, usually when responding to the "Python can't be very fast, it's interpreted" argument. Raw performance is just one aspect in determining suitability of a given technical approach. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
Re: Newbie regular expression and whitespace question
Thanks for the great positive responses. I was close with what I was trying, I guess, but close only counts in horseshoes and um.. something else that close counts in. :-) googleboy -- http://mail.python.org/mailman/listinfo/python-list
Re: Newbie regular expression and whitespace question
"googleboy" <[EMAIL PROTECTED]> wrote:
> Hi.
>
> I am trying to collapse an html table into a single line. Basically,
> anytime I see ">" & "<" with nothing but whitespace between them, I'd
> like to remove all the whitespace, including newlines. I've read the
> how-to and I have tried a bunch of things, but nothing seems to work
> for me:
>
> [snip]
As others have shown you already, you need to use the sub method of the re
module:
import re
regex = re.compile(r'>\s*<')
print regex.sub('><',data)
> For extra kudos (and I confess I have been so stuck on the above
> problem I haven't put much thought into how to do this one) I'd like to
> be able to measure the number of characters between the &
> tags, and then insert a newline character at the end of the next word
> after an arbitrary number of characters. I am reading in to a
> script a bunch of paragraphs formatted for a webpage, but they're all
> on one big long line and I would like to split them for readability.
What I guess you want to do is wrap some text. Do not reinvent the wheel,
there's already a module
for that:
import textwrap
print textwrap.fill(oneBigLongLine, 60)
HTH,
George
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Re: Newbie regular expression and whitespace question
Paul McGuire wrote:
> If you're absolutely stuck on using RE's, then others will have to step
> forward. Meanwhile, here's a pyparsing solution (get pyparsing at
> http://pyparsing.sourceforge.net):
so, let's see. using ...
from pyparsing import *
import re
data = """ ... table example from op ... """
def test1():
LT = Literal("<")
GT = Literal(">")
collapsableSpace = GT + LT
collapsableSpace.setParseAction( replaceWith("><") )
return collapsableSpace.transformString(data)
def test2():
return re.sub(">\s+<", "><", data)
I get
> timeit -s "import test" "test.test1()"
100 loops, best of 3: 6.8 msec per loop
> timeit -s "import test" "test.test2()"
1 loops, best of 3: 33.3 usec per loop
or in other words, five lines instead of one, and a 200x slowdown.
but alright, maybe we should precompile the expressions to get a
fair comparision. adding
LT = Literal("<")
GT = Literal(">")
collapsableSpace = GT + LT
collapsableSpace.setParseAction( replaceWith("><") )
def test3():
return collapsableSpace.transformString(data)
p = re.compile(">\s+<")
def test4():
return p.sub("><", data)
to the first program, I get
> timeit -s "import test" "test.test3()"
100 loops, best of 3: 6.73 msec per loop
> timeit -s "import test" "test.test4()"
1 loops, best of 3: 27.8 usec per loop
that's a 240x slowdown. hmm.
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Re: Newbie regular expression and whitespace question
"googleboy" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Hi.
>
> I am trying to collapse an html table into a single line. Basically,
> anytime I see ">" & "<" with nothing but whitespace between them, I'd
> like to remove all the whitespace, including newlines. I've read the
> how-to and I have tried a bunch of things, but nothing seems to work
> for me:
>
> --
>
> table = open(r'D:\path\to\tabletest.txt', 'rb')
> strTable = table.read()
>
> #Below find the different sort of things I have tried, one at a time:
>
> strTable = strTable.replace(">\s<", "><") #I got this from the module
> docs
>
> strTable = strTable.replace(">.<", "><")
>
> strTable = ">\s+<".join(strTable)
>
> strTable = ">\s<".join(strTable)
>
> print strTable
>
> --
>
> The table in question looks like this:
>
>
>
>
> Introduction
> 3
>
>
>
>
>
> ONE
> Childraising for Parrots
> 11
>
>
>
>
>
> For extra kudos (and I confess I have been so stuck on the above
> problem I haven't put much thought into how to do this one) I'd like to
> be able to measure the number of characters between the &
> tags, and then insert a newline character at the end of the next word
> after an arbitrary number of characters. I am reading in to a
> script a bunch of paragraphs formatted for a webpage, but they're all
> on one big long line and I would like to split them for readability.
>
> TIA
>
> Googleboy
>
If you're absolutely stuck on using RE's, then others will have to step
forward. Meanwhile, here's a pyparsing solution (get pyparsing at
http://pyparsing.sourceforge.net):
---
from pyparsing import *
LT = Literal("<")
GT = Literal(">")
collapsableSpace = GT + LT# matches with or without intervening
whitespace
collapsableSpace.setParseAction( replaceWith("><") )
print collapsableSpace.transformString(data)
---
The reason this works is that pyparsing implicitly skips over whitespace
while looking for matches of collapsable space (a '>' followed by a '<').
When found, the parse action is triggered, which in this case, replaces
whatever was matched with the string "><". Finally, the input data (in this
case your HTML table, stored in the string variable, data) is passed to
transformString, which scans for matches of the collapsableSpace expression,
runs the parse action when they are found, and returns the final transformed
string.
As for word wrapping within ... tags, there are at least two recipes
in the Python Cookbook for word wrapping. Be careful, though, as many HTML
pages are very bad about omitting the trailing tags.
-- Paul
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Re: Newbie regular expression and whitespace question
googleboy a écrit :
> Hi.
>
> I am trying to collapse an html table into a single line. Basically,
> anytime I see ">" & "<" with nothing but whitespace between them, I'd
> like to remove all the whitespace, including newlines. I've read the
> how-to and I have tried a bunch of things, but nothing seems to work
> for me:
>
> --
>
> table = open(r'D:\path\to\tabletest.txt', 'rb')
> strTable = table.read()
>
> #Below find the different sort of things I have tried, one at a time:
>
> strTable = strTable.replace(">\s<", "><") #I got this from the module
> docs
From which module's doc ?
">\s<" is the litteral string ">\s<", not a regular expression. Please
re-read the re module doc, and the re howto (you'll find a link to it in
the re module's doc...)
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Newbie regular expression and whitespace question
Hi.
I am trying to collapse an html table into a single line. Basically,
anytime I see ">" & "<" with nothing but whitespace between them, I'd
like to remove all the whitespace, including newlines. I've read the
how-to and I have tried a bunch of things, but nothing seems to work
for me:
--
table = open(r'D:\path\to\tabletest.txt', 'rb')
strTable = table.read()
#Below find the different sort of things I have tried, one at a time:
strTable = strTable.replace(">\s<", "><") #I got this from the module
docs
strTable = strTable.replace(">.<", "><")
strTable = ">\s+<".join(strTable)
strTable = ">\s<".join(strTable)
print strTable
--
The table in question looks like this:
Introduction
3
ONE
Childraising for Parrots
11
For extra kudos (and I confess I have been so stuck on the above
problem I haven't put much thought into how to do this one) I'd like to
be able to measure the number of characters between the &
tags, and then insert a newline character at the end of the next word
after an arbitrary number of characters. I am reading in to a
script a bunch of paragraphs formatted for a webpage, but they're all
on one big long line and I would like to split them for readability.
TIA
Googleboy
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Re: Simple (newbie) regular expression question
John Machin wrote: André Roberge wrote: Sorry for the simple question, but I find regular expressions rather intimidating. And I've never needed them before ... How would I go about to 'define' a regular expression that would identify strings like __alphanumerical__ as in __init__ (Just to spell things out, as I have seen underscores disappear from messages before, that's 2 underscores immediately followed by an alphanumerical string immediately followed by 2 underscore; in other words, a python 'private' method). Simple one-liner would be good. One-liner with explanation would be better. One-liner with explanation, and pointer to 'great tutorial' (for future reference) would probably be ideal. (I know, google is my friend for that last part. :-) Andre Firstly, some corrections: (1) google is your friend for _all_ parts of your question (2) Python has an initial P and doesn't have private methods. Read this: pat1 = r'__[A-Za-z0-9_]*__' pat2 = r'__\w*__' import re tests = ['x', '__', '', '_', '__!__', '__a__', '__Z__', '__8__', '__xyzzy__', '__plugh'] [x for x in tests if re.search(pat1, x)] ['', '_', '__a__', '__Z__', '__8__', '__xyzzy__'] [x for x in tests if re.search(pat2, x)] ['', '_', '__a__', '__Z__', '__8__', '__xyzzy__'] I've interpreted your question as meaning "valid Python identifier that starts and ends with two [implicitly, or more] underscores". In the two alternative patterns, the part in the middle says "zero or more instances of a character that can appear in the middle of a Python identifier". The first pattern spells this out as "capital letters, small letters, digits, and underscore". The second pattern uses the \w shorthand to give the same effect. You should be able to follow that from the Python documentation. Now, read this: http://www.amk.ca/python/howto/regex/ HTH, John Thanks for it all. It does help! André -- http://mail.python.org/mailman/listinfo/python-list
Re: Simple (newbie) regular expression question
André Roberge wrote: > Sorry for the simple question, but I find regular > expressions rather intimidating. And I've never > needed them before ... > > How would I go about to 'define' a regular expression that > would identify strings like > __alphanumerical__ as in __init__ > (Just to spell things out, as I have seen underscores disappear > from messages before, that's 2 underscores immediately > followed by an alphanumerical string immediately followed > by 2 underscore; in other words, a python 'private' method). > > Simple one-liner would be good. > One-liner with explanation would be better. > > One-liner with explanation, and pointer to 'great tutorial' > (for future reference) would probably be ideal. > (I know, google is my friend for that last part. :-) > > Andre Firstly, some corrections: (1) google is your friend for _all_ parts of your question (2) Python has an initial P and doesn't have private methods. Read this: >>> pat1 = r'__[A-Za-z0-9_]*__' >>> pat2 = r'__\w*__' >>> import re >>> tests = ['x', '__', '', '_', '__!__', '__a__', '__Z__', '__8__', '__xyzzy__', '__plugh'] >>> [x for x in tests if re.search(pat1, x)] ['', '_', '__a__', '__Z__', '__8__', '__xyzzy__'] >>> [x for x in tests if re.search(pat2, x)] ['', '_', '__a__', '__Z__', '__8__', '__xyzzy__'] >>> I've interpreted your question as meaning "valid Python identifier that starts and ends with two [implicitly, or more] underscores". In the two alternative patterns, the part in the middle says "zero or more instances of a character that can appear in the middle of a Python identifier". The first pattern spells this out as "capital letters, small letters, digits, and underscore". The second pattern uses the \w shorthand to give the same effect. You should be able to follow that from the Python documentation. Now, read this: http://www.amk.ca/python/howto/regex/ HTH, John -- http://mail.python.org/mailman/listinfo/python-list
Simple (newbie) regular expression question
Sorry for the simple question, but I find regular expressions rather intimidating. And I've never needed them before ... How would I go about to 'define' a regular expression that would identify strings like __alphanumerical__ as in __init__ (Just to spell things out, as I have seen underscores disappear from messages before, that's 2 underscores immediately followed by an alphanumerical string immediately followed by 2 underscore; in other words, a python 'private' method). Simple one-liner would be good. One-liner with explanation would be better. One-liner with explanation, and pointer to 'great tutorial' (for future reference) would probably be ideal. (I know, google is my friend for that last part. :-) Andre -- http://mail.python.org/mailman/listinfo/python-list
