input() call where text is typed at custom position in the string

Question

This is actually a question I've had since I first started learning Python a year ago. And it is the following: How can I call the input function and have the users type their entry at some point other than the end of the prompt?

To clarify, say I had the string

'Enter file size: MB'

And when called I would want the text to be inserted like so:

Enter file size: 62 MB

Is it possible to recreate this behavior in a function call like the following?

input('Enter file size: {} MB')
# where Python would interpret
# the {} as the position to input text

Answer 1

This works on both Windows and Linux:

import sys
print("                    MB\rEnter file size: ", end = "")
file_size = sys.stdin.readline()[:-1]

On Linux (not Windows), you can also use input(" MB\rEnter file size: ").

Here's a function that makes it a little easier to use:

import sys

def input_multipart(prefix, gap_length, suffix):
    print(" " * (len(prefix) + gap_length) + suffix + "\r" + prefix, end = "")
    return sys.stdin.readline()[:-1]

Usage:

file_size = input_multipart("Enter file size: ", 3, "MB")

Output:

Enter file size:    MB