pandas dataframe读取csv，行的末尾有逗号/没有逗号

Question

我的示例文件如下所示：

1.50424e+09,164.84,164.94,163.4,164.07,09:30:00,1.50424e+12,eAAPL,1.38904e+07,0,22.45,2.64333e+07,847097,18.49,1.54
1.50459e+09,163.8,164.25,158.26,162.2,09:30:00,1.50459e+12,eAAPL,2.54615e+07,0,22.44,2.64646e+07,847097,18.49,1.54
1.50467e+09,162.71,162.99,160.52,162.01,09:30:00,1.50467e+12,eAAPL,1.67919e+07,0,22.67,2.61136e+07,837180,18.27,1.55
1.50485e+09,160.9,161.15,158.62,158.7,09:30:00,1.50485e+12,eAAPL,2.02651e+07,0,22.73,2.48843e+07,832945,18.18,1.56,
1.50511e+09,160.51,162.05,159.89,161.48,09:30:00,1.50511e+12,eAAPL,2.44948e+07,0,22.54,2.50082e+07,819360,17.88,1.59,
1.50476e+09,162.17,163.69,160.36,161.175,09:30:00,1.50476e+12,eAAPL,1.88933e+07,0,22.68,2.58778e+07,836302,18.25,1.56,

请滚动到最右边，你会看到前3行末尾没有逗号，但最后3行有逗号。当我这么做的时候

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它错误地说：

CParserError: Error tokenizing data. C error: Expected 15 fields in line 4, saw 16

我怎么修？在

Answer 1

您可以将usecols与np.arange(0,15)一起使用，忽略csv文件底部三行的尾随列：

from io import StringIO
file = StringIO("""1.50424e+09,164.84,164.94,163.4,164.07,09:30:00,1.50424e+12,eAAPL,1.38904e+07,0,22.45,2.64333e+07,847097,18.49,1.54
1.50459e+09,163.8,164.25,158.26,162.2,09:30:00,1.50459e+12,eAAPL,2.54615e+07,0,22.44,2.64646e+07,847097,18.49,1.54
1.50467e+09,162.71,162.99,160.52,162.01,09:30:00,1.50467e+12,eAAPL,1.67919e+07,0,22.67,2.61136e+07,837180,18.27,1.55
1.50485e+09,160.9,161.15,158.62,158.7,09:30:00,1.50485e+12,eAAPL,2.02651e+07,0,22.73,2.48843e+07,832945,18.18,1.56,
1.50511e+09,160.51,162.05,159.89,161.48,09:30:00,1.50511e+12,eAAPL,2.44948e+07,0,22.54,2.50082e+07,819360,17.88,1.59,
1.50476e+09,162.17,163.69,160.36,161.175,09:30:00,1.50476e+12,eAAPL,1.88933e+07,0,22.68,2.58778e+07,836302,18.25,1.56,""")

f = pd.read_csv(file, usecols=np.arange(0,15), header=None)

print(f.head())

输出：

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Answer 2

如果事先不知道列数，请尝试以下方法：

import io

with open(filename) as f:
    data = f.read() + '\n' # in case there is no `\n` in the last line
    df = pd.read_csv(io.StringIO(data.replace(',\n','\n'))