How can you write to a text file in python 3?

Question

Could someone please explain why this code won't write to a text file? I run the code but a text file is not created and also cannot be opened using f.open("data.txt","r")

f = open("data.txt", "w+")
n = 1
s = 0
for n in range(1, 999999):
    s  += 1/n**2
    print(s, end="\r")
x = s*6
pisquare = math.sqrt(x)
f.write("Pi is ", pisquare)
f.close()

you should take a look at this https://stackoverflow.com/questions/6159900/correct-way-to-write-line-to-file — penguin, Jun 03 '20 at 22:33
Does @penguin's suggestion answer your question? [Correct way to write line to file?](https://stackoverflow.com/questions/6159900/correct-way-to-write-line-to-file) — TheTechRobo the Nerd, Jun 03 '20 at 22:42
If I run your program I get an error which tells me why it's failing to write to the file. — redbirdo, Jun 03 '20 at 22:44

Sy Ker · Answer 1 · 2020-06-03T22:41:12.770

2

The recommended way to open and write to a file is as follow:

with open(file_path, 'w') as file:
    file.write(f'Pi is {pisquare}')

We use the context manager with so the file closes automatically when done with .write(). This prevents memory corruption when your program exits prematurely I believe.

However, as you have probably noticed, your problem comes from this line:

f.write("Pi is ", pisquare)

You are giving .write() two arguments rather than one string.

edited Jun 03 '20 at 22:41

answered Jun 03 '20 at 22:36

Sy Ker

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The solution that I would do is either f-strings or `f.write("Pi is %s" % pisquare")`. – TheTechRobo the Nerd Jun 03 '20 at 22:44
this doesn't explain why the file isn't created at all, though, and the OP is manually closing the file anyway. – juanpa.arrivillaga Jun 03 '20 at 22:51
I can't think of an explanation for it, especially without an error code. – Sy Ker Jun 03 '20 at 23:08

score 1 · Accepted Answer · edited Jun 04 '20 at 01:31

import math
f = open("data.txt", "w+")
n = 1
s = 0
for n in range(1, 999999):
    s  += 1/n**2
    print(s, end="\r")
x = s*6
pisquare = math.sqrt(x)
f.write("Pi is " + str(pisquare))
f.close()

I am able to create the text file. Please check for it in your current directory. But if I understand your code correctly, this is what you are looking for -

import math

n = 1
s = 0
with open("data.txt", "w+") as f:
    for n in range(1, 9999):
        s  += 1/n**2
        print(s, end="\r")
        x = s*6
        pisquare = math.sqrt(x)
        f.write(" Pi is " + str(pisquare) + "\n")

How can you write to a text file in python 3?

2 Answers2