In Python, how to use a file for writing bytes in it and reading as text

Question

I would like to save bytes to a file and then read that file as a text. Can I do it with one with? What should I use, wb, r or wbr?

myBytesVar = b'line1\nline2'
with open('myFile.txt', 'wb') as fw:
    fw.write(myBytesVar)

with open('myFile.txt', 'r') as fr:
    myVar = fr.read()
    print(myVar)

Why can't you just write `myBytesVar` to the file and re-use it with `myVar = myBytesVar.decode('utf-8')`? — Blender, Apr 12 '18 at 07:00
Thanks. Do I need utf8 if I have coding:utf-8 at the beginning of a script? — Hrvoje T, Apr 12 '18 at 07:09
By "with one `with`" do you mean that something like this is acceptable: `with open("myFile.txt", "wb") as outFile, open("myFile.txt", "r") as inFile:`? This should work, although it's just syntactic sugar for a double `with`. — Giacomo Alzetta, Apr 12 '18 at 07:10
@HrvojeT: The encoding that your Python script file itself uses and the encoding your `myFile.txt` uses are two completely different things. — Blender, Apr 12 '18 at 07:12

score 2 · Accepted Answer · answered Apr 12 '18 at 07:18

You don't need to re-read the file if you already have its contents stored in myBytesVar:

myBytesVar = b'line1\nline2'

with open('myFile.txt', 'wb') as fw:
    fw.write(myBytesVar)

myVar = myBytesVar.decode('utf-8')

The encoding Python assumes when reading files as text without an explicit encoding is platform-dependent, so I'm just assuming UTF-8 will work.

score 0 · Answer 2 · edited Apr 12 '18 at 07:26

0

If you want to do it with one "with": When you write it "wb" is good. when you read the file try it

myvar = open('MyVar.txt', 'r').read()
print(myvar)

edited Apr 12 '18 at 07:26

Sraw

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answered Apr 12 '18 at 07:05

Jay Pratap Pandey

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Do I have to close the file then? – Hrvoje T Apr 12 '18 at 07:06
No, what' it need. you already write into file "Myfile.txt" when you see your file "Myfile.txt" it contains line1line2 – Jay Pratap Pandey Apr 12 '18 at 07:13

score 0 · Answer 3 · answered Apr 12 '18 at 07:10

Here is some information on what mode we should use :

The default mode is 'r' (open for reading text, synonym of 'rt'). For binary read-write access, the mode 'w+b' opens and truncates the file to 0 bytes. 'r+b' opens the file without truncation.

Read more here. https://docs.python.org/3/library/functions.html#open

In Python, how to use a file for writing bytes in it and reading as text

3 Answers3