将int或float列表写入CSV

Question

I'm stuck with this problem. I followed many examples of code found here on SO an on official documentation pages, but what I get is:

Python 3.7.0 (default, Aug 22 2018, 20:50:05) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import csv
>>> 
>>> float_list = [1.13, 0.25, 3.28]
>>> 
>>> with open('some.csv', "wb") as file:
...     writer = csv.writer(file, delimiter=',')
...     writer.writerow(float_list)
... 
Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
TypeError: a bytes-like object is required, not 'str'
>>> 

Same thing also with:

int_list=[1,2,3]

Some suggestions?

Answer 1

The "wb" used in your code means that you are writing to the file (using w ) and that you are writing in binary mode (using b ).

For this reason you get the error that you are seeing, you told the writer to expect bytes but then you are sending strings.

Please change:

with open('some.csv', "wb") as file:

To:

with open('some.csv', "w") as file:

Here's more technical details:

On Windows, 'b' appended to the mode opens the file in binary mode, so there are also modes like 'rb', 'wb', and 'r+b'. Python on Windows makes a distinction between text and binary files; the end-of-line characters in text files are automatically altered slightly when data is read or written. This behind-the-scenes modification to file data is fine for ASCII text files, but it'll corrupt binary data like that in JPEG or EXE files.

Here's also a link to the documentation