Check whether string is in CSV

Question

I want to search a CSV file and print either True or False, depending on whether or not I found the string. However, I'm running into the problem whereby it will return a false positive if it finds the string embedded in a larger string of text. E.g.: It will return True if string is foo and the term foobar is in the CSV file. I need to be able to return exact matches.

username = input()  if username in open('Users.csv').read():     print("True") else:     print("False") 

I've looked at using mmap, re and csv module functions, but I haven't got anywhere with them.

EDIT: Here is an alternative method:

import re import csv  username = input()  with open('Users.csv', 'rt') as f:      reader = csv.reader(f)      for row in reader:           re.search(r'\bNOTSUREHERE\b', username) 

Answer 1

when you look inside a csv file using the csv module, it will return each row as a list of columns. So if you want to lookup your string, you should modify your code as such:

import csv  username = input()  with open('Users.csv', 'rt') as f:      reader = csv.reader(f, delimiter=',') # good point by @paco      for row in reader:           for field in row:               if field == username:                   print "is in file" 

but as it is a csv file, you might expect the username to be at a given column:

with open('Users.csv', 'rt') as f:      reader = csv.reader(f, delimiter=',')      for row in reader:           if username == row[2]: # if the username shall be on column 3 (-> index 2)               print "is in file" 

Answer 2

You should have a look at the csv module in python.

is_in_file = False with open('my_file.csv', 'rb') as csvfile:     my_content = csv.reader(csvfile, delimiter=',')     for row in my_content:         if username in row:             is_in_file = True print is_in_file 

It assumes that your delimiter is a comma (replace with the your delimiter. Note that username must be defined previously. Also change the name of the file. The code loops through all the lines in the CSV file. row a list of string containing each element of your row. For example, if you have this in your CSV file: Joe,Peter,Michel the row will be ['Joe', 'Peter', 'Michel']. Then you can check if your username is in that list.