6

Is it possible to manipulate lines of text that have already been printed to the console?

For example,

import time
for k in range(1,100):
     print(str(k)+"/"+"100")
     time.sleep(0.03)
     #>> Clear the most recent line printed to the console
print("ready or not here I come!")

I've seen some things for using custom DOS consoles under Windows, but I would really like something that works on the command_line like does print without any additional canvases.

Does this exist? If it doesn’t, why not?

P.S.: I was trying to use curses, and it was causing problems with my command line behaviour outside of Python. (After erroring out of a Python script with curses in it, my Bash shell stopped printing newline -unacceptable- ).

Peter Mortensen
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kpie
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3 Answers3

12

What you're looking for is:

print("{}/100".format(k), "\r", end="")

\r is carriage return, which returns the cursor to the beginning of the line. In effect, whatever is printed will overwrite the previous printed text. end="" is to prevent \n after printing (to stay on the same line).

A simpler form as suggested by sonrad10 in the comments:

print("{}/100".format(k), end="\r")

Here, we're simply replacing the end character with \r instead of \n.

In Python 2, the same can be achieved with:

print "{}/100".format(k), "\r",
Community
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sirfz
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    @kpie you're using python2, in that case the syntax is `print "{}/100".format(k), "\r",` – sirfz May 13 '15 at 21:11
  • I believe that you can use `print("{}/100".format(k), end="\r")` as a simpler version of this code – AvahW Dec 15 '16 at 14:30
1

What you need are ANSI Command Codes. http://en.wikipedia.org/wiki/ANSI_escape_code#CSI_codes
You also need code to activate ANSI Command Codes. I would use Colorama. https://pypi.python.org/pypi/colorama

OR

Use curses (Python 3.4+) module.

YoungCoder5
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0

The simplest method (at least for Python 2.7) is to use the syntax:

print 'message', '\r',
print 'this new message now covers the previous'

Notice the extra ',' at the end of the first print. This makes print stay on the same line. Meanwhile, the '\r' puts the print at the beginning of that line. So the second print statement overwrites the first.

JoseOrtiz3
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