Shell Programming and Scripting

Hello together,

Yesterday I have recieved the script in the forum which works well.
This script should insert in the previous line, the line that starts with ";".
I'd like this process to recur after any arbitrary sign unless there's a number as a sign at the beginning of a line.


Actual state:

#!/usr/bin/env python


import sys


data=open(sys.argv[1]).read().split("\n")
for n,items in enumerate(data):
if items.startswith("A"):
data[n-1]= data[n-1]+items
data.pop(n)


print '\n'.join(data)




should be:

#!/usr/bin/env python


import sys


data=open(sys.argv[1]).read().split("\n")
for n,items in enumerate(data):
if not items.startswith('[0-9]'):
data[n-1]= data[n-1]+items
data.pop(n)


print '\n'.join(data)




Can I use regular expression at Phyton (startswith)?

I have carried out an investigation but unfortunately up till now I haven't found the right solution.

Any suggestion ??

Thanks in advance!

put your Python code in code tags. Python indentation is important so if you don't put in code tags, its hard to troubleshoot. of course you can use regular expression, using the re module. (i will leave it to you to read the docs if you are interested).
but for this case (and most cases), regular expression is not needed. you just take the first character of the line and check for isdigit(). eg

Code:

import sys
data=open(sys.argv[1]).read().split("\n")
for n,items in enumerate(data):
    if items[0].isdigit(): # check first character is a digit, ie equivalent to [0-9]
        data[n-1]= data[n-1]+items
        data.pop(n)

in a Python string, first character is position 0, second character position 1 and so on. so if you want to get third character of string, its string[2]. read the Python docs and study how Python works.

Thanks again for your fast reply I' going look through the docs!

Something is wrong with the code or with my csv file, I will try to find out what the issue is, and I'll post my result.

Just to clarify what ghostdog said...this "startswith" business is whats known as a "string method", and in string methods (there are many), it uses strings, not regular expressions.

The only way in python to deal with regex's is the "re" module

Code:

import re

the "re" module is pretty involved, but nifty, and in most cases it is overkill.

you know what always helps me in my python coding...that little $10 pocket reference book. I cant tell you how many times I found exactly what I needed in that thing, instead of sifting through docs for 30 minutes. Best $10 I ever spent.

google with keywords takes less than 30 secs.. and free

That's right!

Unfortunately, but the logic of the script is changed.


cat text

001;test;test;test
123;test;test;test
test;test;test
000;;test;test;test


./python.py text

result

123;test;test;test
test;test;test000;;test;test;test
001;test;test;test

Any idea?

dude, so what should the output be like?