将字符串值覆盖到datetime

时间:2018-10-09 08:59:48

标签: python pandas datetime dataframe

我目前有一个数据框,其中有一列包含日期时间值作为对象数据类型。

    col1    col2            col3
0    A       10     2016-06-05 11:00:00
0    B       11     2016-06-04 00:00:00
0    C       12     2016-06-02 05:00:00
0    D       13     2016-06-03 02:00:00

我想做的是将col3转换为日期时间值,这样它就可以给我:

 Year-Month-Day-Hour

稍后再进行一些日期时间功能设计。当我尝试时:

df['col3'] = pd.to_datetime(df['col3'])

我收到此错误:

OutOfBoundsDatetime: Out of bounds nanosecond timestamp: 3008-07-25 00:00:00

有什么想法吗?

谢谢

1 个答案:

答案 0 :(得分:3)

您可以使用参数errors='coerce'将超出限制的值转换为NaT

print (df)
  col1  col2                 col3
0    A    10  2016-06-05 11:00:00
0    B    11  2016-06-04 00:00:00
0    C    12  2016-06-02 05:00:00
0    D    13  3008-07-25 00:00:00

df['col3'] = pd.to_datetime(df['col3'], errors='coerce')
print (df)
  col1  col2                col3
0    A    10 2016-06-05 11:00:00
0    B    11 2016-06-04 00:00:00
0    C    12 2016-06-02 05:00:00
0    D    13                 NaT

Timestamp limitation

In [68]: pd.Timestamp.min
Out[68]: Timestamp('1677-09-21 00:12:43.145225')

In [69]: pd.Timestamp.max
Out[69]: Timestamp('2262-04-11 23:47:16.854775807')

也可以创建Periods,但是从字符串中创建起来并不容易:

def conv(x):
    return pd.Period(year = int(x[:4]), 
                     month = int(x[5:7]), 
                     day = int(x[8:10]),
                     hour = int(x[11:13]), freq='H')

df['col3'] = df['col3'].apply(conv)

print (df)
  col1  col2             col3
0    A    10 2016-06-05 11:00
0    B    11 2016-06-04 00:00
0    C    12 2016-06-02 05:00
0    D    13 3008-07-25 00:00
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