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Re: how to avoid leading white spaces

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On 2011-06-06, rurpy@yahoo.com <rurpy@yahoo.com> wrote:
> On 06/03/2011 02:49 PM, Neil Cerutti wrote:
> Can you find an example or invent one? I simply don't remember
> such problems coming up, but I admit it's possible.
>
> Sure, the response to the OP of this thread.

Here's a recap, along with two candidate solutions, one based on
your recommendation, and one using str functions and slicing. 

(I fixed a specification problem in your original regex, as one
of the lines of data contained a space after the closing ',
making the $ inappropriate)

data.txt:
//ACCDJ         EXEC DB2UNLDC,DFLID=&DFLID,PARMLIB=&PARMLIB,
//         UNLDSYST=&UNLDSYST,DATABAS=MBQV1D0A,TABLE='ACCDJ       '
//ACCT          EXEC DB2UNLDC,DFLID=&DFLID,PARMLIB=&PARMLIB,
//         UNLDSYST=&UNLDSYST,DATABAS=MBQV1D0A,TABLE='ACCT        '
//ACCUM         EXEC DB2UNLDC,DFLID=&DFLID,PARMLIB=&PARMLIB,
//         UNLDSYST=&UNLDSYST,DATABAS=MBQV1D0A,TABLE='ACCUM       '
//ACCUM1        EXEC DB2UNLDC,DFLID=&DFLID,PARMLIB=&PARMLIB,
//         UNLDSYST=&UNLDSYST,DATABAS=MBQV1D0A,TABLE='ACCUM1      ' 
^Z

import re

print("re solution")
with open("data.txt") as f:
    for line in f:
        fixed = re.sub(r"(TABLE='\S+)\s+'", r"\1'", line)
        print(fixed, end='')

print("non-re solution")
with open("data.txt") as f:
    for line in f:
        i = line.find("TABLE='")
        if i != -1:
            begin = line.index("'", i) + 1
            end = line.index("'", begin)
            field = line[begin: end].rstrip()
            print(line[:i] + line[i:begin] + field + line[end:], end='')
        else:
            print(line, end='')

These two solutions print identical output processing the sample
data. Slight changes in the data would reveal divergence in the
assumptions each solution made.

I agree with you that this is a very tempting candidate for
re.sub, and if it probably would have been my first try as well.

-- 
Neil Cerutti

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Re: how to avoid leading white spaces Chris Rebert <clp2@rebertia.com> - 2011-06-01 10:11 -0700
  Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-01 12:39 -0700
    Re: how to avoid leading white spaces Karim <karim.liateni@free.fr> - 2011-06-01 22:34 +0200
    Re: how to avoid leading white spaces Neil Cerutti <neilc@norwich.edu> - 2011-06-02 13:21 +0000
      Re: how to avoid leading white spaces Roy Smith <roy@panix.com> - 2011-06-02 21:57 -0400
        Re: how to avoid leading white spaces MRAB <python@mrabarnett.plus.com> - 2011-06-03 03:41 +0100
        Re: how to avoid leading white spaces Chris Torek <nospam@torek.net> - 2011-06-03 02:58 +0000
          Re: how to avoid leading white spaces Roy Smith <roy@panix.com> - 2011-06-02 23:44 -0400
            Re: how to avoid leading white spaces Chris Angelico <rosuav@gmail.com> - 2011-06-03 13:52 +1000
            Re: how to avoid leading white spaces Chris Angelico <rosuav@gmail.com> - 2011-06-03 13:54 +1000
            Re: how to avoid leading white spaces Chris Torek <nospam@torek.net> - 2011-06-03 04:30 +0000
              Re: how to avoid leading white spaces Nobody <nobody@nowhere.com> - 2011-06-03 14:11 +0100
          Re: how to avoid leading white spaces Nobody <nobody@nowhere.com> - 2011-06-03 14:18 +0100
          Re: how to avoid leading white spaces Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2011-06-04 13:41 +1200
            Re: how to avoid leading white spaces Nobody <nobody@nowhere.com> - 2011-06-04 20:44 +0100
          Re: how to avoid leading white spaces Ian <hobson42@gmail.com> - 2011-06-06 22:04 +0100
            Re: how to avoid leading white spaces Chris Torek <nospam@torek.net> - 2011-06-09 02:32 +0000
        Re: how to avoid leading white spaces Thorsten Kampe <thorsten@thorstenkampe.de> - 2011-06-03 10:32 +0200
      Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-03 05:51 -0700
        Re: how to avoid leading white spaces Neil Cerutti <neilc@norwich.edu> - 2011-06-03 13:17 +0000
          Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-03 08:14 -0700
        Re: how to avoid leading white spaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-06-03 14:25 +0000
          Re: how to avoid leading white spaces "D'Arcy J.M. Cain" <darcy@druid.net> - 2011-06-03 10:58 -0400
          Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-03 12:29 -0700
            Re: how to avoid leading white spaces Neil Cerutti <neilc@norwich.edu> - 2011-06-03 20:49 +0000
              Re: how to avoid leading white spaces Chris Torek <nospam@torek.net> - 2011-06-03 21:45 +0000
                Re: how to avoid leading white spaces Ethan Furman <ethan@stoneleaf.us> - 2011-06-03 15:11 -0700
                Re: how to avoid leading white spaces MRAB <python@mrabarnett.plus.com> - 2011-06-03 23:38 +0100
                Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-05 22:47 -0700
              Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-05 22:44 -0700
                Re: how to avoid leading white spaces Neil Cerutti <neilc@norwich.edu> - 2011-06-06 16:08 +0000
                Re: how to avoid leading white spaces Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-06 10:29 -0600
                Re: how to avoid leading white spaces Neil Cerutti <neilc@norwich.edu> - 2011-06-06 17:17 +0000
                Re: how to avoid leading white spaces Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-06 11:40 -0600
                Re: how to avoid leading white spaces Neil Cerutti <neilc@norwich.edu> - 2011-06-06 17:56 +0000
                Re: how to avoid leading white spaces Ethan Furman <ethan@stoneleaf.us> - 2011-06-06 10:48 -0700
                Re: how to avoid leading white spaces Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-06 11:42 -0600
            Re: how to avoid leading white spaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-06-04 02:05 +0000
              Re: how to avoid leading white spaces MRAB <python@mrabarnett.plus.com> - 2011-06-04 03:24 +0100
                Re: how to avoid leading white spaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-06-04 04:59 +0000
              Re: how to avoid leading white spaces Roy Smith <roy@panix.com> - 2011-06-03 22:30 -0400
                Re: how to avoid leading white spaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-06-04 05:14 +0000
                Re: how to avoid leading white spaces Roy Smith <roy@panix.com> - 2011-06-04 09:39 -0400
                Re: how to avoid leading white spaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-06-05 00:44 +0000
                Re: how to avoid leading white spaces rusi <rustompmody@gmail.com> - 2011-06-04 09:36 -0700
                Re: how to avoid leading white spaces Nobody <nobody@nowhere.com> - 2011-06-04 21:02 +0100
                Re: how to avoid leading white spaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-06-05 01:01 +0000
                Re: how to avoid leading white spaces Chris Angelico <rosuav@gmail.com> - 2011-06-04 16:04 +1000
              Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-05 23:03 -0700
                Re: how to avoid leading white spaces Chris Torek <nospam@torek.net> - 2011-06-06 07:11 +0000
                Re: how to avoid leading white spaces "Octavian Rasnita" <orasnita@gmail.com> - 2011-06-06 11:51 +0300
                Re: how to avoid leading white spaces Chris Angelico <rosuav@gmail.com> - 2011-06-06 19:01 +1000
                Re: how to avoid leading white spaces rusi <rustompmody@gmail.com> - 2011-06-06 07:33 -0700
                Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-07 11:37 -0700
                Re: how to avoid leading white spaces Roy Smith <roy@panix.com> - 2011-06-07 20:30 -0400
                Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-08 07:38 -0700
                Re: how to avoid leading white spaces rusi <rustompmody@gmail.com> - 2011-06-08 09:14 -0700
                Re: how to avoid leading white spaces rusi <rustompmody@gmail.com> - 2011-06-08 01:27 -0700
                Re: how to avoid leading white spaces Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2011-06-06 15:29 +0000
                Re: how to avoid leading white spaces Ian Kelly <ian.g.kelly@gmail.com> - 2011-06-06 10:06 -0600
                Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-07 09:00 -0700
                Re: how to avoid leading white spaces Duncan Booth <duncan.booth@invalid.invalid> - 2011-06-08 09:01 +0000
                Re: how to avoid leading white spaces "rurpy@yahoo.com" <rurpy@yahoo.com> - 2011-06-08 07:39 -0700
          Re: how to avoid leading white spaces rusi <rustompmody@gmail.com> - 2011-06-05 04:17 -0700

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