[Tutor] searching data from a list read from a file

[Peter Otten]

Lea Parker wrote:

[Lea, please reduce the number of empty lines in your posted source code.]

> When you have time I would like some advice on where to go. I have created
> a program that reads charge account numbers from a file. The user is to
> enter a charge account number from the list presented and the program
> should then tell them whether they have entered a valid or invalid number.
> My problem at this stage (and yes there a probably more than this one), is
> when I run the program it tells me the charge account number is always
> invalid even when I put a correct number in. Below is my code because I am
> thinking that perhaps it is an indent issue maybe.

Hint: 

What is the type of the values in the account_number list?
What is the type of the value stored in the search variable?
What's the result of a comparison like

42 == "42"

in Python?

> """This program reads the contents of a file into a list. Asks the user
> 
> to enter a charge account number and will determine the validity of the
> 
> number entered to return a message of either valid or invalid.
> 
>  
> 
> Written by: Leonie Parker 11428070
> 
> Subject:    ITC Principles of programming
> 
> Assignment: 2b"""
> 
>  
> 
> def main():
> 
>     try:
> 
>         # Open file for reading
> 
>         infile = open('charge_accounts.txt', 'r')
> 
>  
> 
>         # Read the contents of the file inot a lsit
> 
>         account_number = infile.readlines()
> 
>  
> 
>         #Convert each element into an int
> 
>         index = 0
> 
>         while index != len(account_number):
> 
>             account_number[index] = int(account_number[index])
> 
>             index += 1
> 
>  
> 
>         # Print the contents of the list
> 
>         print account_number
> 
>  
> 
>         #Get an account number to search for
> 
>         search = raw_input('Enter a charge account number: ')
> 
>  
> 
>         #Determine whether the product number is in thelist
> 
>         if search in account_number:
> 
>             print search, 'charge account number is VALID'
> 
>         else:
> 
>             print search, 'charge account number is INVALID'
> 
>  
> 
>         infile.close()
> 
>         
> 
>     except ValueError:
> 
>         print 'file open error message'
> 
>                   
> 
> #Call the main function
> 
> main()
> 
>  
> 
>  
> 
>  
> 
> Thanks in advance