Whether it's super or not, python is pretty beginner. I hate file operations too much.

Purpose of the article

It's not limited to python, but ** I hate file operations too much **, so I'll try file operations a little. File operations here are at the level of opening, writing, and closing files.

For the time being, I think it will take some time for a third party to make the article meaningful.

Try file operations.

step1

I ran the following code.

file_step1.py

f1 = open('testfile1.txt')
f1.write(123)
f1.write(456)
f1.close

I was scolded as follows.

C:\_temp_work\fileA>python file_step1.py
Traceback (most recent call last):
  File "file_step1.py", line 2, in <module>
    f1.write(123)
TypeError: write() argument must be str, not int

C:\_temp_work\fileA>

The above is an extra error, but I corrected the error.

file_step1a.py

f1 = open('testfile1.txt')
f1.write('123')
f1.write('456')
f1.close

Also, I was scolded.

C:\_temp_work\fileA>python file_step1a.py
Traceback (most recent call last):
  File "file_step1a.py", line 2, in <module>
    f1.write('123')
io.UnsupportedOperation: not writable

C:\_temp_work\fileA>

Fixed.

file_step1b.py

f1 = open('testfile1.txt', mode='w')
f1.write('123')
f1.write('456')
f1.close

This time, there is no problem.

C:\_temp_work\fileA>python file_step1b.py

C:\_temp_work\fileA>

testfile1.txt Can be done.

The contents are

testfile1.txt

123456

no problem.

Now that I'm interested in binaries ** I tried mode ='wb'. ** **

file_step2.py

f1 = open('testfile1.txt', mode='wb')
f1.write('123')
f1.write('456')
f1.close

Also, I was scolded.

C:\_temp_work\fileA>python file_step2.py
Traceback (most recent call last):
  File "file_step2.py", line 2, in <module>
    f1.write('123')
TypeError: a bytes-like object is required, not 'str'

C:\_temp_work\fileA>

from now on

to be continued.