How To Search For A String Case-insensitively Without Regular Expressions?

I want to search a file for all lines containing a given string without matching case. How can I make this code case-insensitive? with open(logfile) as inf: for line in inf:

Solution 1:

with open(logfile) as fin:
    for line in fin:
        if var.lower() in line.lower():  # makes this case insensitive
            print 'found', line.rstrip() # You will be printing double new lines 
                                         #  without rstrip here