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pythonpython-3.xstdout

Overwriting/clearing previous console line

My problem is, that I want to be able to overwrite/clear previous printed line in python console. This question has been asked many times (Python - Remove and Replace Printed items for example), however with the very same code that is (the answer marked as correct, for me prints out nothing at all):

for i in range(10):
    print("Loading" + "." * i)
    time.sleep(1)
    sys.stdout.write("\033[F") # Cursor up one line
    sys.stdout.write("\033[K") # Clear to the end of line

I get the output (In python IDLE) :

Loading
[F[KLoading.
[F[KLoading..
[F[KLoading...
[F[KLoading....
[F[KLoading.....
[F[KLoading......
[F[KLoading.......
[F[KLoading........
[F[KLoading.........
[F[KLoading..........
[F[K

Any ideas? I googled a lot, nothing works really. It either prints out nothing or just does not overwrite.

If that helps, I am running windows 8.1 and Python 3.51. Running the code trough cmd doesn't affect anything.

Also, adding sys.stdout.flush() does not help.

Solution

  • You need to run your program from the command line, not from within IDLE.

    Then, this should work:

    import sys
import time

for i in range(10):
    sys.stdout.write("\r" + "Loading" + "." * i)
    time.sleep(1)
    sys.stdout.flush()
print()

    The \r goes to the beginning of the line. So you have to make sure the string you print is at least as long as the one before. Otherwise, you will see parts of the previous print.