Search Specific Field In Text File

Suppose I have a file named abc.txt which contains the following data. I am an newbie. So please help Nathan Johnson 23 M Mary Kom 28 F John Keyman 32 M Edward Stella

Solution 1:

You can do something like this, if you want to search via a particular piece of information. So say, the user wants to search through firstname for John. This is how you would do it:

#!usr/bin/python
import sys
class Records:
    def __init__(self, firstname, lastname, age, gender):
        self.fname = firstname
        self.lname = lastname
        self.age = age
        self.gender = gender

f= open("abc","r")
list_of_records = [Records(*line.split()) for line in f]
search_term = "John"
for record in list_of_records:
    if record.firstname == search_term:
        print "We found him!"
        print record.firstname, record.lastname, record.age, record.gender

If the user gave both a firstname and a gender, then you can do something like this:

for record in list_of_records:
    if record.firstname == "John" and record.gender = "M":
        print "We found him!"
        print record.firstname, record.lastname, record.age, record.gender

Also, always remember to close your file streams, so when you call open, you are actually opening a file stream, so at the end of the script, always close them, like so f.close(). If you use with, then you do not need to worry about closing.

Solution 2:

For a more compact and flexible solution, you can use the namedtuple type from the standard library:

import collections

record_tuple = collections.namedtuple('Record',
                      ['Firstname', 'Lastname', 'Age', 'Gender'])

n = raw_input("Enter %s :" % ' '.join('%s.%s' % (i, name) for i, name in enumerate(record_tuple._fields, 1)))
n = int(n)

StringSearch = raw_input('Enter %s :' % record_tuple._fields[n-1])

for line in open('abc'):
    record = record_tuple(*line.split())
    if record[n-1] == StringSearch:
        print ' '.join(record)

This way, you can generalize the search code.