Get text contents of what has been printed python

Question

Lets say I print the following code

print("""
THE RUSSIAN PEASANT ALGORITHM
-----------------------------
times two values x and y together


""")

x=int(raw_input("raw_input x: "))
y=int(raw_input("raw_input y: "))

print("x"+" "*(10)+"y")

while x!=1:
      x=x/2
      y=y*2

      print(str(x)+" "*10+str(y))

This prints the results of an algorithm, appropiately to the numbers that the user enterred.Now if I wished to get a variable containing all that had been outputted to the python console, how would I go about that?

EDIT: To clarify the reason I want the output if so basically I can clear the screen with "CLS" and reprint everything I've already printed but with the even x values crossed out as you are supposed to do with the russian peasant algorithm.

I don't know of a way to do that however a way I can think of would be to define your own print function that logs everything that was printed into a list. — EDD, Mar 03 '16 at 17:33
Yeah but then you have to make a function for the raw_input and recreate a lot of the print functionality it seems like a lot of hassle surely there must be an easy way to return what has been outputted on the screen? — user2592835, Mar 03 '16 at 17:46
Well I want a complete python script that I can run not a separate program or file — user2592835, Mar 03 '16 at 17:50

score 9 · Answer 1 · edited Jun 20 '20 at 09:12

9

Its all about redefine your stdout to some inmemory stream.

You can use printing to string. See python2 docs - Reading and writing strings as file, python3 docs - Core tools for working with streams.

Do what you what with that string even print it with regular print.

Code Python2:

import sys
import StringIO
old_stdout = sys.stdout # Memorize the default stdout stream
sys.stdout = buffer = StringIO.StringIO()

print('123')
a = 'HeLLo WorLd!'
print(a)
# Call your algorithm function.
# etc...

sys.stdout = old_stdout # Put the old stream back in place

whatWasPrinted = buffer.getvalue() # Return a str containing the entire contents of the   buffer.
print(whatWasPrinted) # Why not to print it?
buffer.close()

Code Python3:

import sys
import io

old_stdout = sys.stdout # Memorize the default stdout stream
sys.stdout = buffer = io.StringIO()

print('123')
a = 'HeLLo WorLd!'
print(a)
# Call your algorithm function.
# etc...

sys.stdout = old_stdout # Put the old stream back in place

whatWasPrinted = buffer.getvalue() # Return a str containing the entire contents of the buffer.
print(whatWasPrinted) # Why not to print it?
print(123)

whatWasPrinted then can be changed, printed to regular stdout, etc.

edited Jun 20 '20 at 09:12

Community

1
1

answered Mar 03 '16 at 17:37

Ivan Gritsenko

4,166
2
20
34

The documentation hasnt really helped with my problem – user2592835 Mar 03 '16 at 17:45
@user2592835, check the link again, I've found something more relevant. See code as well. – Ivan Gritsenko Mar 03 '16 at 17:57
This won't work, you are going to get an error using StringIO which you could see by just running the code. – Padraic Cunningham Mar 03 '16 at 18:00
@Padraic Cunningham, It was tested in python 3.4 on my machine. Also tested it on [repl.it](https://repl.it/languages/python3) and [Codeforces](http://codeforces.com/problemset/customtest). No errors. Could you please clarify what exactly are you talking about? – Ivan Gritsenko Mar 03 '16 at 18:03
The OP is not using python3, try your code using python2 – Padraic Cunningham Mar 03 '16 at 18:04
@Padraic Cunningham, you are right. In python2 it doesn ot work. – Ivan Gritsenko Mar 03 '16 at 18:08
yep that is why I used a TemporaryFile, you need unicode for StringIO which works fine in python3 but chokes on python2 – Padraic Cunningham Mar 03 '16 at 18:09
@Padraic Cunningham, I've added Python2 version. – Ivan Gritsenko Mar 03 '16 at 18:24
I think the OP wants the output tee'd, if you redirect you won't see the output to the screen – Padraic Cunningham Mar 03 '16 at 18:25
This is lovely for text in console. For text printed with logger, use LogCapture as discussed here https://stackoverflow.com/a/35037409/248616 – Nam G VU Jun 28 '19 at 18:49

Adak Vira · Answer 2 · 2020-08-24T08:32:40.540

2

you can do this by writing in a text file:

sys.stdout = open("test.txt", "w")

##    Your Code    ##
    
sys.stdout.close()

if you need it in your program you can read from the text file.

printed_text=open("test.txt", "r").readlines()

edited Aug 24 '20 at 08:32

answered Aug 24 '20 at 07:07

Adak Vira

21
2

score 1 · Answer 3 · edited May 23 '17 at 10:30

What you seem to want is to tee the output, if we make a minor tweak to the Tee implementation here using a tempfile you can write to a TemporaryFile then get the output from that:

import sys
from tempfile import TemporaryFile

class Tee(object):
    def __init__(self):
        self.file = TemporaryFile()
        self.stdout = sys.stdout
        sys.stdout = self

    def __del__(self):
        sys.stdout = self.stdout
        self.file.close()

    def write(self, data):
        self.file.write(data)
        self.file.write(data.rstrip()+"\n")
        self.stdout.flush()
t = Tee()
print("""
THE RUSSIAN PEASANT ALGORITHM
-----------------------------
times two values x and y together


""")

x = int(raw_input("raw_input x: "))
y = int(raw_input("raw_input y: "))    
print("x" + " " * (10) + "y")   
while x != 1:
    x = x / 2
    y = y * 2  
    print(str(x) + " " * 10 + str(y))   
t.file.seek(0)
print(t.file.read())

Traceback (most recent call last): File "C:/Python27/DECISION/Section 1/Russian_Peasant_Algorithm.py", line 59, in print(t.file.read()) File "C:/Python27/DECISION/Section 1/Russian_Peasant_Algorithm.py", line 20, in write self.file.write(data) IOError: [Errno 0] Error >>> — user2592835, Mar 03 '16 at 17:54

score -1 · Answer 4 · answered Mar 03 '16 at 17:42

I'm not sure why you want to do this, so this might not help you, but it's possible to get all values printed in console by executing your script from another script.

in a new file :

import subprocess
linetorun = ["python", "yourscript.py"]
proc= subprocess.Popen(linetorun,stdout=subprocess.PIPE,stderr=subprocess.STDOUT)
printedtoconsole,errormessage=proc.communicate()
with open("output.txt","w+") as outfile:
    f.write(x)

should do the trick. communicate() with the options set in Popen will give you the console output. This might need some adaptation for unix.

Get text contents of what has been printed python

4 Answers4

Code Python2:

Code Python3:

Linked