requestion regarding regular expression

[Kelie]

Hello,

I'm trying to analyze some autolisp code with python. In the file to
be analyzed there are many functions. Each function begins with a
"defun" statement. And before that, there may or may not have comment
line(s), which begins with ";". My goal is to export each function
into separate files, with comments, if there is any. Below is the code
that I'm struggling with:

path = "C:\\AutoCAD\\LSP\\Sub.lsp"
string = file(path, 'r').read()

import re
pat = "\\;+.+\\n\\(DEFUN"
p = re.compile(pat,re.I)

iterator = p.finditer(string)
spans = [match.span() for match in iterator]

for i in range(min(15, len(spans))):
print string[spans[i][0]:spans[i][1]]

The code above runs fine. But it only takes care of the situation in
which there is exactly one comment line above the "defun" statement.
How do I repeat the sub-pattern "\\;+.+\\n" here?
For example if I want to repeat this pattern 0 to 10 times, I know
"\\;+.+\\n{0:10 }\\(DEFUN" does not work. But don't know where to put
"{0:10}". As a work around, I tried to use
pat = "|".join(["\\;+.+\\n" *i+ "\\(DEFUN" for i in range(11)]), and it
turned out to be very slow. Any help?

Thank you.

Kelie

[Kent Johnson]

Re: requestion regarding regular expression

Kelie wrote:[color=blue]
> Hello,
>
> I'm trying to analyze some autolisp code with python. In the file to
> be analyzed there are many functions. Each function begins with a
> "defun" statement. And before that, there may or may not have comment
> line(s), which begins with ";". My goal is to export each function
> into separate files, with comments, if there is any. Below is the code
> that I'm struggling with:
>
>

>
> path = "C:\\AutoCAD\\LSP\\Sub.lsp"
> string = file(path, 'r').read()
>
> import re
> pat = "\\;+.+\\n\\(DEFUN"
> p = re.compile(pat,re.I)
>
> iterator = p.finditer(string)
> spans = [match.span() for match in iterator]
>
> for i in range(min(15, len(spans))):
>     print string[spans[i][0]:spans[i][1]]
>
>

>
> The code above runs fine. But it only takes care of the situation in
> which there is exactly one comment line above the "defun" statement.[/color]

ISTM you don't need regex here, a simple line processor will work.
Something like this (untested):

path = "C:\\AutoCAD\\L SP\\Sub.lsp"
lines = open(path).read lines()

# Find the starts of all the functions
starts = [i for i, line in enumerate(lines ) if line.startswith ('(DEFUN')]

# Check for leading comments
for i, start in starts:
while start > 0 and lines[start-1].startswith(';' ):
starts[i] = start = start-1

# Now starts should be a list of line numbers for the start of each function

Kent

[BartlebyScrivener]

Re: requestion regarding regular expression

Kent,

Running

path = "d:/emacs files/emacsinit.txt"
lines = open(path).read lines()
# my defun lines are lowercase,
# next two lines are all on one
starts = [i for i, line in enumerate(lines ) if
line.startswith ('(defun')]
for i, start in starts:
while start > 0 and lines[start-1].startswith(';' ):
starts[i] = start = start-1
print starts

I get

File "D:\Python\find lines.py", line 7, in __main__
for i, start in starts:
TypeError: unpack non-sequence

Also, I don't understand the "i for i", but I don't understand a lot of
things yet :)

thanks,

rick

[Felipe Almeida Lessa]

Re: requestion regarding regular expression

Em Sex, 2006-04-14 às 07:47 -0700, BartlebyScriven er escreveu:[color=blue]
> starts = [i for i, line in enumerate(lines ) if
> line.startswith ('(defun')][/color]

This line makes a list of integers. enumerate gives you a generator that
yields tuples consisting of (integer, object), and by "i for i, line"
you unpack the tuple into "(i, line)" and pick just "i".
[color=blue]
> for i, start in starts:[/color]

Here you try to unpack the elements of the list "starts" into "(i,
start)", but as we saw above the list contains just "i", so an exception
is raised.

I don't know what you want, but...

starts = [i, line for i, line in enumerate(lines ) if
line.startswith ('(defun')]

or

starts = [x for x in enumerate(lines ) if x[1].startswith('(d efun')]

....may (or may not) solve your problem.

--
Felipe.

[Kent Johnson]

Re: requestion regarding regular expression

BartlebyScriven er wrote:[color=blue]
> Kent,
>
> Running
>
> path = "d:/emacs files/emacsinit.txt"
> lines = open(path).read lines()
> # my defun lines are lowercase,
> # next two lines are all on one
> starts = [i for i, line in enumerate(lines ) if
> line.startswith ('(defun')]
> for i, start in starts:
> while start > 0 and lines[start-1].startswith(';' ):
> starts[i] = start = start-1
> print starts
>
> I get
>
> File "D:\Python\find lines.py", line 7, in __main__
> for i, start in starts:
> TypeError: unpack non-sequence[/color]

Sorry, should be
for i, start in enumerate(start s):

start is a specific start line, i is the index of that start line in the
starts array (so the array can be modified in place).

Kent

[BartlebyScrivener]

Re: requestion regarding regular expression

That's it. Thank you! Very instructive.

Final:

path = "d:/emacs files/emacsinit.txt"
lines = open(path).read lines()
# next two lines all on one
starts = [i for i, line in enumerate(lines ) if
line.startswith ('(defun')]
for i, start in enumerate(start s):
while start > 0 and lines[start-1].startswith(';' ):
starts[i] = start = start-1
print starts

[Scott David Daniels]

Re: requestion regarding regular expression

BartlebyScriven er wrote:[color=blue]
> That's it. Thank you! Very instructive.
>
> Final:
>
> path = "d:/emacs files/emacsinit.txt"
> lines = open(path).read lines()
> # next two lines all on one
> starts = [i for i, line in enumerate(lines ) if
> line.startswith ('(defun')]
> for i, start in enumerate(start s):
> while start > 0 and lines[start-1].startswith(';' ):
> starts[i] = start = start-1
> print starts
>[/color]
If you don't want to hold the whole file in memory, this gets the
starts a result at a time:

def starts(source):
prelude = None
for number, line in enumerate(sourc e): # read and number a line
if line[0] == ';':
if prelude is None:
prelude = number # Start of commented region
# else: this line just extends previous prelude
else:
if line.startswith ('(defun'):
# You could append to a result here, but yield lets
# the first found one get out straightaway.
if prelude is None:
yield number
else:
yield prelude
prelude = None


path = "d:/emacs files/emacsinit.txt"
source = open(path)
try:
for line in starts(source):
print line,
# could just do: print list(starts(sou rce))
finally:
source.close()
print

--
-Scott David Daniels
scott.daniels@a cm.org

[BartlebyScrivener]

Re: requestion regarding regular expression

This is very helpful.

I wasn't the OP. I'm just learning, but I'm on the verge of making my
own file searching scripts. This will be a huge help. Thanks for
posting, and especially thanks for the comments in the code. Big help!

rick

[Kelie]

Re: requestion regarding regular expression

Thanks to both of you, Kent and Scott.