Print file out 1 character at a time in the terminal - Python

Question

This program opens a file and prints the text out to the terminal 1 character at a time and at a predetermined speed using time.sleep()

Simple and maybe, if you think like me, pretty cool..

GitHub

from time import sleep
import sys

BLINK = 0.2
chars_in_line = 50

def open_file(fn):
    with open(fn, "r") as f:
        for line in f:
            if line:
                yield line

def type_out_text_to_line(text, end="", sep="", line_chars=None, blink=0.2):
    if not text:
        return ""

    c = line_chars
    for i, j in enumerate(text):
        sys.stdout.flush()
        sleep(blink)
        print(j, end=end, sep=sep)
        if line_chars:
            if i + 1 == c:
                print()
                c += line_chars
    return ""


print("\n\tSTART PRINTING\n")

for text in open_file('example.txt'):
    if len(text) > 1:
        print(type_out_text_to_line(text, line_chars=chars_in_line, blink=BLINK, sep=""))

print("\n\tEND PRINTING\n")

Answer 1

I would recommend just using the built in functionality of print to do the flushing. Though I am an advocate for breaking things out into classes and functions, you should use built in functionality when you can.

Making code complex for no reason results in two things:

1) More bugs.
2) More programmers who want to wring your neck down the road because they have to maintain or fix your software.

So you can simplify your code like this:

from time import sleep

BLINK = 0.2

print("\n\tSTART PRINTING\n")

with open('example.txt') as f:
    for line in f:
        for char in line:
            print(char, flush=True, end='')
            sleep(BLINK)

print("\n\tEND PRINTING\n")

If you want to make this into a function (to make it easier to import/export) then I would do following:

from time import sleep

def time_print_file(filename, print_rate, **print_kwargs):
    """
    INPUT:
        filename: The path to the file to be printing
        print_rate: The delay used to print each character
        print_kwargs: keyword arguments accepted by pythons
           print statement. (Except `end` and `flush`)
    """
    print_kwargs.pop('flush', None) # We don't allow the flush print-keyword
    print_kwargs.pop('end', None) # We don't allow the end print-keyword
    with open(filename) as f:
        for line in f:
            for char in line:
                print(char, flush=True, end='', **print_kwargs)
                sleep(print_rate)


if __name__ == '__main__':
    print("\n\tSTART PRINTING\n")
    time_print_file(filename='example.txt', print_rate=0.2)
    print("\n\tEND PRINTING\n")