Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
655 views
in Technique[技术] by (71.8m points)

python - KeyError when indexing Pandas dataframe

I am trying to read data from a csv file into a pandas dataframe, and access the first column 'Date'

import pandas as pd
df_ticks=pd.read_csv('values.csv', delimiter=',')
print(df_ticks.columns)
df_ticks['Date']

produces the following result

Index([u'Date', u'Open', u'High', u'Low', u'Close', u'Volume'], dtype='object')
KeyError: u'no item named Date'

If I try to acces any other column like 'Open' or 'Volume' it is working as expected

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

As mentioned by alko, it is probably extra character at the beginning of your file. When using read_csv, you can specify encoding to deal with encoding and heading character, known as BOM (Byte order mark)

df = pd.read_csv('values.csv', delimiter=',', encoding="utf-8-sig")

This question finds some echoes on Stackoverflow: Pandas seems to ignore first column name when reading tab-delimited data, gives KeyError


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...