Flush output in for loop in Jupyter notebook

Question

I want to print out i in my iteration on Jupyter notebook and flush it out. After the next iteration, I'll print the next i. I tried solutions from this question and this question, however, it just print out 0123...9 without flushing the output for me. Here is my working code:

import sys
import time

for i in range(10):
    sys.stdout.write(str(i)) # or print(i, flush=True) ?
    time.sleep(0.5)
    sys.stdout.flush()

these are my setup: ipython 5.1, python 3.6. Maybe, I missed something in the previous solution?

score 15 · Accepted Answer · answered Mar 31 '17 at 23:01

15

#Try this:
import sys
import time

for i in range (10):  
    sys.stdout.write('\r'+str(i))
    time.sleep(0.5)

'\r' will print at the beginning of the line

answered Mar 31 '17 at 23:01

jose_bacoy

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thanks! this solution works for me. seems like we don't really need flush output at all. – titipata Mar 31 '17 at 23:29

Alperen · Answer 2 · 2020-10-04T19:30:56.773

10

The first answer is correct but you don't need sys package. You can use the end parameter of the print function. It specifies what to print at the end, and its default value is \n(newline) (docs1, docs2). Use \r(carriage return) instead.

import time

for i in range (10):  
    print(i, end="\r")
    time.sleep(0.5) # This line is to see if it's working or not

edited Oct 04 '20 at 19:30

answered Apr 17 '19 at 21:39

Alperen

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1

Thanks @Alperen! This one is actually handy! – titipata Apr 18 '19 at 01:15

score 2 · Answer 3 · edited Nov 07 '20 at 17:11

2

Try this

for i in range (10):  
    print("\r", end=str(i))

edited Nov 07 '20 at 17:11

Striped

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answered Nov 07 '20 at 15:47

Илья Царенков

21
1

Flush output in for loop in Jupyter notebook

3 Answers3

'\r' will print at the beginning of the line

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