How do I split a combo list in a large text file?

Question

my problem is that I have a very large database of emails and passwords and I need to send it to a mysql database.

The .txt file format is something like this:

emailnumberone@gmail.com:password1
emailnumbertwo@gmail.com:password2
emailnumberthree@gmail.com:password3
emailnumberfour@gmail.com:password4
emailnumberfive@gmail.com:password5

My idea is to make a loop that takes the line and make it a variable, search the ":" and pick the text before, send it to the db and then the same with the after part of the line. How do I do this?

Answer 1

Short program with some error handling:

Create demo data file:

t = """
emailnumberone@gmail.com:password1
emailnumbertwo@gmail.com:password2
emailnumberthree@gmail.com:password3
emailnumberfour@gmail.com:password4
emailnumberfive@gmail.com:password5
k
: """

with open("f.txt","w") as f: f.write(t)

Parse data / store:

def store_in_db(email,pw):
    # replace with db access code 
    # see    http://bobby-tables.com/python
    # for parametrized db code in python (or the API of your choice)
    print("stored: ", email, pw)


with open("f.txt") as r:
    for line in r:
        if line.strip():  # weed out empty lines
            try:
                email, pw = line.split(":",1) # even if : in pw: only split at 1st :
                if email.strip() and pw.strip(): # only if both filled
                    store_in_db(email,pw)
                else:
                    raise ValueError("Something is empty: '"+line+"'")

            except Exception as ex:
                print("Error: ", line, ex)

Output:

stored:  emailnumberone@gmail.com password1

stored:  emailnumbertwo@gmail.com password2

stored:  emailnumberthree@gmail.com password3

stored:  emailnumberfour@gmail.com password4

stored:  emailnumberfive@gmail.com password5

Error:  k
 not enough values to unpack (expected 2, got 1)
Error:  :  Something is empty: ': '

---

Edit: According to What characters are allowed in an email address? - a ':' may be part of the first part of an email if quoted.

This would theoretically allow inputs as

`"Cool:Emailadress@google.com:coolish_password"` 

which will get errors with this code. See Talip Tolga Sans answer for how to break down the splitting differently to avoid this problem.