Extract Words from a file

Question

I open a file using python to find whether a predefined set of words are present in the opened file or not. I took the predefined set of words in a list and opened the file

Answer 1

This code will show what words are present in the file, given that the word exactly matches, and is not preceded or followed by punctuation or other characters, and is of the same case. With some minor adjustment, the code could be made more forgiving.

words = set(['hello', 'world', 'testing'])
f     = open('testfile.txt', 'rb')
data  = set(f.read().split())
print words.intersection(data)

Answer 2

import re

def get_words_from_string(s):
    return set(re.findall(re.compile('\w+'), s.lower()))

def get_words_from_file(fname):
    with open(fname, 'rb') as inf:
        return get_words_from_string(inf.read())

def all_words(needle, haystack):
    return set(needle).issubset(set(haystack))

def any_words(needle, haystack):
    return set(needle).intersection(set(haystack))

search_words = get_words_from_string("This is my test")
find_in = get_words_from_string("If this were my test, I is passing")

print any_words(search_words, find_in)

print all_words(search_words, find_in)

returns

set(['this', 'test', 'is', 'my'])
True

Answer 3

You can do a few things

• Call file.readlines() and split the entire text on your desired delimiter if your text isn't large
• Call read() and do it bytes at a time

Check out the pydocs for file - http://docs.python.org/release/2.5.2/lib/bltin-file-objects.html