Read text file and look for certain words from key word list

Question

I am new to Python, and I am trying to build a script where I import text_file_1 that contains a body of text. I want the script to read the body of text, and look for certain words that I have defined in a list called (key_words) that contain words with a Capital letter in the beginning (Nation) and lowercase (nation). After Python does the searching, it will output the list of words vertically in a new text file called "List of Words", along with the number of times that word occurs in the body. If I read text_file_2 with a body of text, it will do the same, but ADD to the List of Words from the original file.

Example:

List of Words

File 1:

God: 5
Nation: 4
creater: 8
USA: 3 

File 2:

God: 10
Nation: 14
creater: 2
USA: 1

Here is what I have so far:

from sys import argv
from string import punctuation

script = argv[0] all_filenames = argv[1:]

print "Text file to import and read: " + all_filenames
print "\nReading file...\n"
text_file = open(all_filenames, 'r')
all_lines = text_file.readlines()
#print all_lines
text_file.close()

for all_filenames in argv[1:]:
   print "I get: " + all_filenames

print "\nFile read finished!"
#print "\nYour file contains the following text information:"
#print "\n" + text_file.read()

#~ for word, count in word_freq.items():
    #~ print word, count

keyWords = ['God', 'Nation', 'nation', 'USA', 'Creater', 'creater', 'Country', 'Almighty',
             'country', 'People', 'people', 'Liberty', 'liberty', 'America', 'Independence', 
             'honor', 'brave', 'Freedom', 'freedom', 'Courage', 'courage', 'Proclamation',
             'proclamation', 'United States', 'Emancipation', 'emancipation', 'Constitution',
             'constitution', 'Government', 'Citizens', 'citizens']

for word in keyWords:
    if word in word_freq:
        output_file.write( "%s: %d\n" % (word, word_freq[word]) )

output_file = open("List_of_words.txt", "w")

for word in keyWords:
    if word in word_freq:
        output_file.write( "%s: %d\n" % (word, word_freq[word]) )

output_file.close()

Maybe use this code somehow?

import fileinput
for line in fileinput.input('List_of_words.txt', inplace = True):
    if line.startswith('Existing file that was read'):
        #if line starts Existing file that was read then do something here
        print "Existing file that was read"
    elif line.startswith('New file that was read'):
        #if line starts with New file that was read then do something here
        print "New file that was read"
    else:
        print line.strip()

Answer 1

This way you have result on the screen.

from sys import argv
from collections import Counter
from string import punctuation

script, filename = argv

text_file = open(filename, 'r')

word_freq = Counter([word.strip(punctuation) for line in text_file for word in line.split()])

#~ for word, count in word_freq.items():
    #~ print word, count

key_words = ['God', 'Nation', 'nation', 'USA', 'Creater', 'creater'
             'Country', 'country', 'People', 'people', 'Liberty', 'liberty',
             'honor', 'brave', 'Freedom', 'freedom', 'Courage', 'courage']

for word in key_words:
    if word in word_freq:
        print word, word_freq[word]

Now you have to save it in file.

For more files use

for filename in argv[1:]:
   # do your job

---

EDIT:

With this code (my_script.py)

for filename in argv[1:]:
   print( "I get", filename )

You can run script

python my_script.py file1.txt file2.txt file3.txt 

and get

I get file1.txt 
I get file2.txt 
I get file3.txt 

You can use it to count words in many files.

-

Using readlines() you read all lines into memory so you need more memory - for very, very big file it can be problem.

In current version Counter() count all words in all lines - test it - but use less memory.
So using readlines() you get the same word_freq but you use more memory.

-

writelines(list_of_result) will not add "\\n" after every line - and don't add ':' in "God: 3"

Better use something similar to

output_file = open("List_of_words.txt", "w")

for word in key_words:
    if word in word_freq:
        output_file.write( "%s: %d\n" % (word, word_freq[word]) )

output_file.close()

---

EDIT: new version - it append result to the end of List_of_words.txt

from sys import argv
from string import punctuation
from collections import *

keyWords = ['God', 'Nation', 'nation', 'USA', 'Creater', 'creater', 'Country', 'Almighty',
             'country', 'People', 'people', 'Liberty', 'liberty', 'America', 'Independence', 
             'honor', 'brave', 'Freedom', 'freedom', 'Courage', 'courage', 'Proclamation',
             'proclamation', 'United States', 'Emancipation', 'emancipation', 'Constitution',
             'constitution', 'Government', 'Citizens', 'citizens']


for one_filename in argv[1:]:

    print "Text file to import and read:", one_filename
    print "\nReading file...\n"

    text_file = open(one_filename, 'r')
    all_lines = text_file.readlines()
    text_file.close()

    print "\nFile read finished!"

    word_freq = Counter([word.strip(punctuation) for line in all_lines for word in line.split()])

    print "Append result to the end of file: List_of_words.txt"

    output_file = open("List_of_words.txt", "a")

    for word in keyWords:
        if word in word_freq:
            output_file.write( "%s: %d\n" % (word, word_freq[word]) )

    output_file.close()

---

EDIT: write sum of results in one file

from sys import argv
from string import punctuation
from collections import *

keyWords = ['God', 'Nation', 'nation', 'USA', 'Creater', 'creater', 'Country', 'Almighty',
             'country', 'People', 'people', 'Liberty', 'liberty', 'America', 'Independence', 
             'honor', 'brave', 'Freedom', 'freedom', 'Courage', 'courage', 'Proclamation',
             'proclamation', 'United States', 'Emancipation', 'emancipation', 'Constitution',
             'constitution', 'Government', 'Citizens', 'citizens']

word_freq = Counter()

for one_filename in argv[1:]:

    print "Text file to import and read:", one_filename
    print "\nReading file...\n"

    text_file = open(one_filename, 'r')
    all_lines = text_file.readlines()
    text_file.close()

    print "\nFile read finished!"

    word_freq.update( [word.strip(punctuation) for line in all_lines for word in line.split()] )

print "Write sum of results: List_of_words.txt"

output_file = open("List_of_words.txt", "w")

for word in keyWords:
    if word in word_freq:
        output_file.write( "%s: %d\n" % (word, word_freq[word]) )

output_file.close()