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pythoncsvpython-3.xencodingutf-8

Python 3 CSV file giving UnicodeDecodeError: 'utf-8' codec can't decode byte error when I print

I have the following code in Python 3, which is meant to print out each line in a csv file.

import csv
with open('my_file.csv', 'r', newline='') as csvfile:
    lines = csv.reader(csvfile, delimiter = ',', quotechar = '|')
    for line in lines:
        print(' '.join(line))

But when I run it, it gives me this error:

UnicodeDecodeError: 'utf-8' codec can't decode byte 0x96 in position 7386: invalid start byte

I looked through the csv file, and it turns out that if I take out a single ñ (little n with a tilde on top), every line prints out fine.

My problem is that I've looked through a bunch of different solutions to similar problems, but I still have no idea how to fix this, what to decode/encode, etc. Simply taking out the ñ character in the data is NOT an option.

Solution

  • We know the file contains the byte b'\x96' since it is mentioned in the error message:

    UnicodeDecodeError: 'utf-8' codec can't decode byte 0x96 in position 7386: invalid start byte

    Now we can write a little script to find out if there are any encodings where b'\x96' decodes to ñ:

    import pkgutil
import encodings
import os

def all_encodings():
    modnames = set([modname for importer, modname, ispkg in pkgutil.walk_packages(
        path=[os.path.dirname(encodings.__file__)], prefix='')])
    aliases = set(encodings.aliases.aliases.values())
    return modnames.union(aliases)

text = b'\x96'
for enc in all_encodings():
    try:
        msg = text.decode(enc)
    except Exception:
        continue
    if msg == 'ñ':
        print('Decoding {t} with {enc} is {m}'.format(t=text, enc=enc, m=msg))

    which yields

    Decoding b'\x96' with mac_roman is ñ
Decoding b'\x96' with mac_farsi is ñ
Decoding b'\x96' with mac_croatian is ñ
Decoding b'\x96' with mac_arabic is ñ
Decoding b'\x96' with mac_romanian is ñ
Decoding b'\x96' with mac_iceland is ñ
Decoding b'\x96' with mac_turkish is ñ

    Therefore, try changing

    with open('my_file.csv', 'r', newline='') as csvfile:

    to one of those encodings, such as:

    with open('my_file.csv', 'r', encoding='mac_roman', newline='') as csvfile: