If I had the following code:
for x in range(10):
print(x)
I would get the output of
1
2
etc..
What I would like to do is instead of printing a newline, I want to replace the previous value and overwrite it with the new value on the same line.
Simple Version
One way is to use the carriage return ('\r') character to return to the start of the line without advancing to the next line.
Python 3
for x in range(10):
print(x, end='\r')
print()
Python 2.7 forward compatible
from __future__ import print_function
for x in range(10):
print(x, end='\r')
print()
Python 2.7
for x in range(10):
print '{}\r'.format(x),
print
Python 2.0-2.6
for x in range(10):
print '{0}\r'.format(x),
print
In the latter two (Python 2-only) cases, the comma at the end of the print statement tells it not to go to the next line. The last print statement advances to the next line so your prompt won't overwrite your final output.
Line Cleaning
If you can’t guarantee that the new line of text is not shorter than the existing line, then you just need to add a “clear to end of line” escape sequence, '\x1b[1K' ('\x1b' = ESC):
for x in range(75):
print('*' * (75 - x), x, end='\x1b[1K\r')
print()
Since I ended up here via Google but am using Python 3, here's how this would work in Python 3:
for x in range(10):
print("Progress {:2.1%}".format(x / 10), end="\r")
Related answer here: How can I suppress the newline after a print statement?
#Mike DeSimone answer will probably work most of the time. But...
for x in ['abc', 1]:
print '{}\r'.format(x),
-> 1bc
This is because the '\r' only goes back to the beginning of the line but doesn't clear the output.
If POSIX support is enough for you, the following would clear the current line and leave the cursor at its beginning:
print '\x1b[2K\r',
It uses ANSI escape code to clear the terminal line. More info can be found in wikipedia and in this great talk.
Other approach
This other, (arguably worse) solution I have found looks like this:
last_x = ''
for x in ['abc', 1]:
print ' ' * len(str(last_x)) + '\r',
print '{}\r'.format(x),
last_x = x
-> 1
One advantage is that it will work on windows too.
I had the same question before visiting this thread. For me the sys.stdout.write worked only if I properly flush the buffer i.e.
for x in range(10):
sys.stdout.write('\r'+str(x))
sys.stdout.flush()
Without flushing, the result is printed only at the end out the script
Suppress the newline and print \r.
print 1,
print '\r2'
or write to stdout:
sys.stdout.write('1')
sys.stdout.write('\r2')
for x in range(10):
time.sleep(0.5) # shows how its working
print("\r {}".format(x), end="")
time.sleep(0.5) is to show how previous output is erased and new output is printed
"\r" when its at the start of print message , it gonna erase previous output before new output.
Try this:
import time
while True:
print("Hi ", end="\r")
time.sleep(1)
print("Bob", end="\r")
time.sleep(1)
It worked for me. The end="\r" part is making it overwrite the previous line.
WARNING!
If you print out hi, then print out hello using \r, you’ll get hillo because the output wrote over the previous two letters. If you print out hi with spaces (which don’t show up here), then it will output hi. To fix this, print out spaces using \r.
This works on Windows and python 3.6
import time
for x in range(10):
time.sleep(0.5)
print(str(x)+'\r',end='')
Here's a cleaner, more "plug-and-play", version of #Nagasaki45's answer. Unlike many other answers here, it works properly with strings of different lengths. It achieves this by clearing the line with just as many spaces as the length of the last line printed print. Will also work on Windows.
def print_statusline(msg: str):
last_msg_length = len(getattr(print_statusline, 'last_msg', ''))
print(' ' * last_msg_length, end='\r')
print(msg, end='\r')
sys.stdout.flush() # Some say they needed this, I didn't.
setattr(print_statusline, 'last_msg', msg)
Usage
Simply use it like this:
for msg in ["Initializing...", "Initialization successful!"]:
print_statusline(msg)
time.sleep(1)
This small test shows that lines get cleared properly, even for different lengths:
for i in range(9, 0, -1):
print_statusline("{}".format(i) * i)
time.sleep(0.5)
I couldn't get any of the solutions on this page to work for IPython, but a slight variation on #Mike-Desimone's solution did the job: instead of terminating the line with the carriage return, start the line with the carriage return:
for x in range(10):
print '\r{0}'.format(x),
Additionally, this approach doesn't require the second print statement.
The accepted answer is not perfect. The line that was printed first will stay there and if your second print does not cover the entire new line, you will end up with garbage text.
To illustrate the problem save this code as a script and run it (or just take a look):
import time
n = 100
for i in range(100):
for j in range(100):
print("Progress {:2.1%}".format(j / 100), end="\r")
time.sleep(0.01)
print("Progress {:2.1%}".format(i / 100))
The output will look something like this:
Progress 0.0%%
Progress 1.0%%
Progress 2.0%%
Progress 3.0%%
What works for me is to clear the line before leaving a permanent print. Feel free to adjust to your specific problem:
import time
ERASE_LINE = '\x1b[2K' # erase line command
n = 100
for i in range(100):
for j in range(100):
print("Progress {:2.1%}".format(j / 100), end="\r")
time.sleep(0.01)
print(ERASE_LINE + "Progress {:2.1%}".format(i / 100)) # clear the line first
And now it prints as expected:
Progress 0.0%
Progress 1.0%
Progress 2.0%
Progress 3.0%
I'm a bit surprised nobody is using the backspace character. Here's one that uses it.
import sys
import time
secs = 1000
while True:
time.sleep(1) #wait for a full second to pass before assigning a second
secs += 1 #acknowledge a second has passed
sys.stdout.write(str(secs))
for i in range(len(str(secs))):
sys.stdout.write('\b')
Here's my solution! Windows 10, Python 3.7.1
I'm not sure why this code works, but it completely erases the original line. I compiled it from the previous answers. The other answers would just return the line to the beginning, but if you had a shorter line afterwards, it would look messed up like hello turns into byelo.
import sys
#include ctypes if you're on Windows
import ctypes
kernel32 = ctypes.windll.kernel32
kernel32.SetConsoleMode(kernel32.GetStdHandle(-11), 7)
#end ctypes
def clearline(msg):
CURSOR_UP_ONE = '\033[K'
ERASE_LINE = '\x1b[2K'
sys.stdout.write(CURSOR_UP_ONE)
sys.stdout.write(ERASE_LINE+'\r')
print(msg, end='\r')
#example
ig_usernames = ['beyonce','selenagomez']
for name in ig_usernames:
clearline("SCRAPING COMPLETE: "+ name)
Output - Each line will be rewritten without any old text showing:
SCRAPING COMPLETE: selenagomez
Next line (rewritten completely on same line):
SCRAPING COMPLETE: beyonce
(Python3) This is what worked for me. If you just use the \010 then it will leave characters, so I tweaked it a bit to make sure it's overwriting what was there. This also allows you to have something before the first print item and only removed the length of the item.
print("Here are some strings: ", end="")
items = ["abcd", "abcdef", "defqrs", "lmnop", "xyz"]
for item in items:
print(item, end="")
for i in range(len(item)): # only moving back the length of the item
print("\010 \010", end="") # the trick!
time.sleep(0.2) # so you can see what it's doing
One more answer based on the prevous answers.
Content of pbar.py:
import sys, shutil, datetime
last_line_is_progress_bar=False
def print2(print_string):
global last_line_is_progress_bar
if last_line_is_progress_bar:
_delete_last_line()
last_line_is_progress_bar=False
print(print_string)
def _delete_last_line():
sys.stdout.write('\b\b\r')
sys.stdout.write(' '*shutil.get_terminal_size((80, 20)).columns)
sys.stdout.write('\b\r')
sys.stdout.flush()
def update_progress_bar(current, total):
global last_line_is_progress_bar
last_line_is_progress_bar=True
completed_percentage = round(current / (total / 100))
current_time=datetime.datetime.now().strftime('%m/%d/%Y-%H:%M:%S')
overhead_length = len(current_time+str(current))+13
console_width = shutil.get_terminal_size((80, 20)).columns - overhead_length
completed_width = round(console_width * completed_percentage / 100)
not_completed_width = console_width - completed_width
sys.stdout.write('\b\b\r')
sys.stdout.write('{}> [{}{}] {} - {}% '.format(current_time, '#'*completed_width, '-'*not_completed_width, current,
completed_percentage),)
sys.stdout.flush()
Usage of script:
import time
from pbar import update_progress_bar, print2
update_progress_bar(45,200)
time.sleep(1)
update_progress_bar(70,200)
time.sleep(1)
update_progress_bar(100,200)
time.sleep(1)
update_progress_bar(130,200)
time.sleep(1)
print2('some text that will re-place current progress bar')
time.sleep(1)
update_progress_bar(111,200)
time.sleep(1)
print('\n') # without \n next line will be attached to the end of the progress bar
print('built in print function that will push progress bar one line up')
time.sleep(1)
update_progress_bar(111,200)
time.sleep(1)
Better to overwrite the whole line otherwise the new line will mix with the old ones if the new line is shorter.
import time, os
for s in ['overwrite!', 'the!', 'whole!', 'line!']:
print(s.ljust(os.get_terminal_size().columns - 1), end="\r")
time.sleep(1)
Had to use columns - 1 on Windows.
This worked for me, using Python 3.7.9 within Spyder, in Windows:
from IPython.display import clear_output
from time import sleep
def print_and_overwrite(text):
'''Remember to add print() after the last print that you want to overwrite.'''
clear_output(wait=True)
print(text, end='\r')
for i in range(15):
#I print the results backwards (from 15 to 1), to test shorter strings
message = "Iteration %d out of 15" %(15-i)
print_and_overwrite(message)
sleep(0.5)
print() #This stops the overwriting
print("This will be on a new line")
Anyway if somebody wants to overprint (clear) a many lines previously printed in stdout, than this answer should be helpful for him. (Thanks Thijmen Dam for the nice article Overwrite Previously Printed Lines)
In ANSI console you can use special sequences:
\033[1A and \033[K
First of them lift up a cursor, second - erase a line entirely.
Example of the clearing a console (Python 3):
LINE_UP = '\033[1A'
LINE_CLEAR = '\033[K'
CONSOLE_HEIGHT = 24 #lines
def clear_console():
for a in range(CONSOLE_HEIGHT):
print(LINE_UP, end=LINE_CLEAR, flush=True)
or eventually simply (will clear screen and move cursor to 0,0):
print('\033[2J', end='', flush=True)
If you want just positioning cursor, then use this:
print('\033[<L>;<C>f', end='', flush=True)
where <L> and <C> are Line and Column correspondingly.
Handful reference for you ANSI escape sequences
with open(args.identfile) as indetifierfile, \
open(args.elementtxt) as elementfile:
for identifier_line, element_line in izip(identifierfile, elementfile):
ident_split = identifier_line.split(".")
el_split = elementfile_line.split(".")
print ident_split[0]
print ident_split[1]
print el_split[0] //print for debug, bad programming practice apparently. I know.
print el_split[1]
if el_split is None: //tried to use this to start from the beginning of the file and continue loop? I don't know if it's valid.
el_split.seek(0)
So I tried to read and process these two files. Where the print statements are I was going to put some code to put the stuff from the files together and output it to a file. The stuff in the element file doesn't have as much as identifier files. I would like to start from the beginning of the element file everytime it reaches end of file? I'm not sure how to go about this I tried the .seek
But that's not working. How do I go about doing this? To continue the loop and reading identifier file but start from the beginning of the element file.
You can try using itertools.cycle:
from itertools import izip, cycle
with open(args.identfile) as indetifierfile, \
open(args.elementtxt) as elementfile:
for identifier_line, element_line in izip(identifierfile, cycle(elementfile)):
ident_split = identifier_line.split(".")
el_split = elementfile_line.split(".")
print ident_split[0]
print ident_split[1]
print el_split[0]
print el_split[1]
I think the code below will do what you want. Get the length of the element file. Add to your counter every pass of the for loop. Once the counter reaches the length of the element file minus 1 (because arrays start at 0), it will reset the counter to 0 and start from the beginning of the elementfile while still going on the identifierfile.
count = 0
elementLength = len(elementfile)
for i in range(len(identifierfile)):
ident_split = identifierfile[i].split(".")
el_split = elementfile[count].split(".")
print ident_split[0]
print ident_split[1]
print el_split[0]
print el_split[1]
if count < (elementLength-1):
count = count + 1
else:
count = 0
I have a text file with 2000 words, one word on each line. I'm trying to create a code that prints out two random words from the textfile on the same line every 10 seconds. The beginning part of my text file is shown below:
slip
melt
true
therapeutic
scarce
visitor
wild
tickle
.
.
.
The code that I've written is:
from time import sleep
import random
my_file = open("words.txt", "r")
i = 1
while i > 0:
number_1 = random.randint(0, 2000)
number_2 = random.randint(0, 2000)
word_1 = my_file.readline(number_1)
word_2 = my_file.readline(number_2)
print(word_1.rstrip() + " " + word_2.rstrip())
i += 1
sleep(10)
When I execute the code instead of printing two random words it starts printing all the words in order from the top of the text. I'm not sure why this is happening since number_1 and number_2 are inside the loop so every time two words print number_1 and number_2 should be changed to two other random numbers. I don't think replacing number_1 and number_2 outside of the loop will work either since they'll be fixed to two values and the code will just keep on printing the same two words. Does anyone know what I can do to fix the code?
readline() doesn't take any parameters and just returns the next line in your file input*. Instead, try to create a list using readlines(), then choose randomly from that list. So here, you'd make word_list = my_file.readlines(), then choose random elements from word_list.
*Correction: readline() does take a parameter of the number of bytes to read. The documentation for the function doesn't seem to explicitly state this. Thanks E. Ducateme!
my_file.readline(number_1) does not do what you want. The argument for readline is the max size in bytes of a line you can read rather than the position of the line in the file.
As the other answer mentioned, a better approach is to first read the lines into a list and then randomly select words from it:
from time import sleep
import random
my_file = open("words.txt", "r")
words = my_file.readlines()
i = 1
while i > 0:
number_1 = random.randint(0, 2000)
number_2 = random.randint(0, 2000)
word_1 = words[number_1]
word_2 = words[number_2]
print(word_1.rstrip() + " " + word_2.rstrip())
i += 1
sleep(10)
I'm trying to make program using Python.
I want to be able to pipe program through another program:
" #EXAMPLE " ./my_python | another programme "
Here is the code I have so far.
This code saves output to file:
#!/usr/bin/env python
import os, random, string
# This is not my own code
''' As far asi know, It belongs to NullUserException. Was found on stackoverflow.com'''
length = 8
chars = string.ascii_letters.upper()+string.digits
random.seed = (os.urandom(1024))
# my code
file_out = open('newRa.txt','w') # Create a 'FILE' to save Generated Passwords
list1=[]
while len(list1) < 100000:
list1.append(''.join(random.choice(chars) for i in range(length)))
for item in list1:
file_out.write('%s\n' % item)
file_out.close()
file_out1=open('test.txt','w')
for x in list1:
file_out1.write('%s\n' %x[::-1])
This is the code I have trying to pipe it through another program:
#!/usr/bin/env python
import os,string,random,sys
length = 8
chars = string.ascii_letters.upper()+string.digits
random.seed = (os.urandom(1024))
keep=[]
keep1=[]
while len(keep)<1000:
keep.append(''.join(random.choice(chars) for i in range(length)))
print '\n',keep[::-1]
for x in keep:
keep1.append(x[::-1])
while len(keep1) < 1000:
print keep1
I have tried chmod and using the script as a executable.
Ok sorry for my lack of google search.
sys.stdout is the answer
#!/usr/bin/env python
import os,string,random,sys
length = 8
chars = string.ascii_letters.upper()+string.digits
random.seed = (os.urandom(1024))
keep=[]
while len(keep)<1000:
keep = (''.join(random.choice(chars) for i in range(length)))
print sys.stdout.write(keep)
sys.stdout.flush()
I stripped my code down (as it makes it a lot faster, But I'm getting this when execute
my code........
P5DBLF4KNone
DVFV3JQVNone
CIMKZFP0None
UZ1QA3HTNone
How do I get rid of the 'None' on the end?
What I have done to cause this ?
Should This Be A Seperate Question??