如何在Python中将CSV列读取为字符串

Question

I wrote code with pandas in order to pass in a CSV and retrieve a column, and then I have more code that is supposed to split the data using the re library, but it throws an error stating "TypeError: expected string or bytes-like object."

I believe I just need to convert the CSV into a string before running re on it, but I can't figure out how.

The column in the CSV has data which look like: 'HB1.A1D62no.0016, HB31.N33NO.89, HB 54 .N338'

import pandas as pd

data = pd.read_csv('HB_Lib.csv', delimiter = ',')
s = [data[['Call Number']]]

import re

pattern = r"(^[a-z]+)\s*(\d+(?:\.\d+)?)"
print(list(map("".join, [re.findall(pattern, part, flags=re.I)[0] for part in s])))

Traceback:

Traceback (most recent call last):

  File "C:/Python/test2.py", line 8, in <module>
    print(list(map("".join, [re.findall(pattern, part, flags=re.I)[0] for part in s])))

  File "C:/Python/test2.py", line 8, in <listcomp>
    print(list(map("".join, [re.findall(pattern, part, flags=re.I)[0] for part in s])))

  File "C:\Python37\lib\re.py", line 223, in findall
    return _compile(pattern, flags).findall(string)

TypeError: expected string or bytes-like object

Answer 1

data['Call Number'] = data['Call Number'].astype(str)

Answer 2

I think the first thing you should do is to remove the external square brakets when declaring s.

So, obtaining something like:

a = data[['something']]