Why does my typer's print make a new line for every character?

Question

I am running python 3.X, in console. Why does my typer's print make a new line for every character? Here is the code:

import msvcrt as m
def wait():
    m.getch()

print(" ")
string = """
code
"""

for i in string:
    wait()
    print(str(i).replace("\n", ""))

Here is the output:



c
o
d
e

Here is the output I want:


code

Take some time to look over the docs before asking here: https://docs.python.org/3/library/functions.html#print — 001, Oct 17 '19 at 16:29

score 1 · Answer 1 · answered Oct 17 '19 at 16:21

1

The print() function has an argument called end which is by default... You guessed it! '\n'.

If you don't want to have the default new-line, you can do:

print(..., end="")

So doing:

string = """
code
"""

for i in string:
    print(i, end="")

Gives:


code

answered Oct 17 '19 at 16:21

Tomerikoo

18,379
16
47
61

It's blank when I print with end="", until I reach the end of the string. – Oct 17 '19 at 16:30
1

@DustinMachat Try adding `flush=True` to `print`. – 001 Oct 17 '19 at 16:32

score 0 · Answer 2 · answered Oct 17 '19 at 16:22

0

print takes an optional keyword argument end, whose value defaults to \n'. You need to change that to the empty string. It's also simpler to just ignore i == "\n" rather than replace it with "".

for i in string():
    wait()
    if i != "\n":
        print(i, end='')

answered Oct 17 '19 at 16:22

chepner

497,756
71
530
681

It prints nothing until you reach the end of the string. – Oct 17 '19 at 16:30
See https://stackoverflow.com/questions/107705/disable-output-buffering. – chepner Oct 17 '19 at 16:38
1

You may also simply want to use `m.putch` instead of `print`. – chepner Oct 17 '19 at 16:39

score 0 · Accepted Answer · answered Oct 17 '19 at 16:44

Ok, I figured it out on my own. having this:

print(someString, end=anything)

causes the output to not load in. This is because the code is buffering, and holds onto the output. My solution was to refresh my output every print, using sys.stdout.flush(). Here is the code that lets the output go:

import sys
sys.stdout.flush()

Here is my final "pretend-typer" code:

import msvcrt as m
import sys
def wait():
    m.getch()

print(" ")
stringy = """code"""

for i in stringy:
    wait()
    s = i
    print(s, end="")
    sys.stdout.flush()

Replace stringy with whatever you want the user to type. This does not work in emulators such as PyCharm or Eclipse, unless you run in console mode. This needs to be in a console.

score 0 · Answer 4 · answered Oct 17 '19 at 18:32

Print has a flush method built-in with Python 3.3 and later. If using Python 3.3+ is an option, you should be able to skip calling sys.stdout.flush().

import msvcrt as m

def wait():
    m.getch()

print(" ")
my_string = "code"

for c in my_string:
    wait()
    print(str(c), end='', flush=True)

Why does my typer's print make a new line for every character?

4 Answers4