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Mar 14th, 2008

find string in file

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Hi friends !!

I'm neophite about python, my target is to create a programa that
find a specific string in text file.
How can do it?

Thanks
fel

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parsifal67

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Mar 14th, 2008

Re: find string in file

The simplest way, but maybe not the most efficient for large files, is this:

python Syntax (Toggle Plain Text)
# sample text for testing
# could come from a text file read like this:
"""
infile = open("my_text.txt","r")
text = infile.read()
infile.close()
"""
 
text = """\
My name is Fred Flintstone and I am a famous TV
star.  I have as much authority as the Pope, I
just don't have as many people who believe it.
"""
 
search = "Fred"
index = text.find(search)
print search, "found at index", index
 
"""
my ouput (index is zero based) -->
Fred found at index 11
"""
# sample text for testing
# could come from a text file read like this:
"""
infile = open("my_text.txt","r")
text = infile.read()
infile.close()
"""

text = """\
My name is Fred Flintstone and I am a famous TV
star.  I have as much authority as the Pope, I
just don't have as many people who believe it.
"""

search = "Fred"
index = text.find(search)
print search, "found at index", index

"""
my ouput (index is zero based) -->
Fred found at index 11
"""

Note that find() only finds the first occurrence of the search word!

ZZucker

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Mar 14th, 2008

Re: find string in file

FWIW this will find all occurrences of a word in a string. Also note that if you are looking for "the" it will give a hit for "then". If you only want the word, you have to search with spaces added, " the " -assuming string.lower() and that punctuation is removed

Python Syntax (Toggle Plain Text)
found=the_string.find(word)
while found > -1:
     print word, "found at location", found
     found=the_string.find(word, found+1)
found=the_string.find(word)
while found > -1:
     print word, "found at location", found
     found=the_string.find(word, found+1)

Last edited by woooee; Mar 14th, 2008 at 7:33 pm.

woooee

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Nearly a Posting Maven

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Nov 7th, 2009

-1

Re: find string in file

I kinda have the sane problem, but i want to extract the text ocr several lines.. not just a word...
Can somone tell me how to use a RE for this?
Thanks!

mitsuevo

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Nov 7th, 2009

Re: find string in file

You should really start a new thread of your own!

The string function find() can find a subtext within a larger text, as will re.findall(). The advantage of find() is that it will give you the location in the form of an index.

Last edited by vegaseat; Nov 7th, 2009 at 12:05 pm.

vegaseat

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DaniWeb's Hypocrite

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Nov 7th, 2009

Re: find string in file

Click to Expand / Collapse Quote originally posted by vegaseat ...

You should really start a new thread of your own!

The string function find() can find a subtext within a larger text, as will re.findall(). The advantage of find() is that it will give you the location in the form of an index.

Thanks, but i'm a bit unsure on using the index since the length of data tends to change within the search area...

And sorry about not starting a new thread... cos in another hobby forum that i'm part of we try to post questions in a thread thats already started with a similar question so that other readers can also look back on the old answer.. i guess it depends on the forum

Thanks again guys. i'm new to DaniWeb and am loving it here! you guys are amazingly helpful!!!

mitsuevo

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Nov 7th, 2009

Re: find string in file

Ah, the pros and cons on posting on an old thread.
If you are interested in a regex solution, I would start a new thread and put regex in the title.

sneekula

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Nov 7th, 2009

Re: find string in file

A friend just gave me a basic (not very professinal, but easy to move around) solution... trying that out... if it doesnt work, i sure will throw the problem at you guys again

mitsuevo

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