将pandas df写入csv时出现Unicode编码错误

Question

I cleaned 400 excel files and read them into python using pandas and appended all the raw data into one big df.

Then when I try to export it to a csv:

df.to_csv("path",header=True,index=False)

I get this error:

UnicodeEncodeError: 'ascii' codec can't encode character u'\xc7' in position 20: ordinal not in range(128)

Can someone suggest a way to fix this and what it means?

Thanks

Answer 1

You have unicode values in your DataFrame. Files store bytes, which means all unicode have to be encoded into bytes before they can be stored in a file. You have to specify an encoding, such as utf-8 . For example,

df.to_csv('path', header=True, index=False, encoding='utf-8')

If you don't specify an encoding, then the encoding used by df.to_csv defaults to ascii in Python2, or utf-8 in Python3.

Answer 2

Adding an answer to help myself google it later:

One trick that helped me is to encode a problematic series first, then decode it back to utf-8. Like:

df['crumbs'] = df['crumbs'].map(lambda x: x.encode('unicode-escape').decode('utf-8'))

This would get the dataframe to print correctly too.