pandas :将日期"object"转换为int [英] Pandas: convert date 'object' to int

问题描述

我有一个Pandas数据框，我需要将带有日期的列转换为int，但是不幸的是，所有给定的解决方案都以错误结尾(如下)

I have a Pandas dataframe and I need to convert a column with dates to int but unfortunately all the given solutions end up with errors (below)

test_df.info()

<class 'pandas.core.frame.DataFrame'>
Data columns (total 4 columns):
Date        1505 non-null object
Avg         1505 non-null float64
TotalVol    1505 non-null float64
Ranked      1505 non-null int32
dtypes: float64(2), int32(1), object(1) 

样本数据:

    Date        Avg             TotalVol  Ranked
0   2014-03-29  4400.000000     0.011364    1
1   2014-03-30  1495.785714     4.309310    1
2   2014-03-31  1595.666667     0.298571    1
3   2014-04-01  1523.166667     0.270000    1
4   2014-04-02  1511.428571     0.523792    1

我认为我已经尝试了所有方法，但没有任何效果

I think that I've tried everything but nothing works

test_df['Date'].astype(int):

TypeError:int()参数必须是字符串，类似字节的对象或数字，而不是'datetime.date'

TypeError: int() argument must be a string, a bytes-like object or a number, not 'datetime.date'

test_df['Date']=pd.to_numeric(test_df['Date']):

TypeError:位置0处的对象类型无效

TypeError: Invalid object type at position 0

test_df['Date'].astype(str).astype(int):

ValueError:以10为底的int()无效文字:"2014-03-29"

ValueError: invalid literal for int() with base 10: '2014-03-29'

test_df['Date'].apply(pd.to_numeric, errors='coerce'):

将整个列转换为NaNs

Converts the entire column to NaNs

推荐答案

test_df['Date'].astype(int)给您错误的原因是您的日期仍包含连字符"-".首先通过执行test_df['Date'].str.replace("-","")抑制它们，然后可以将第一种方法应用于所得的序列.因此，整个解决方案将是:

The reason why test_df['Date'].astype(int) gives you an error is that your dates still contain hyphens "-". First suppress them by doing test_df['Date'].str.replace("-",""), then you can apply your first method to the resulting series. So the whole solution would be :

test_df['Date'].str.replace("-","").astype(int) 请注意，如果您的"日期"列不是字符串对象，则此方法将不起作用，通常是在Pandas已将您的系列解析为TimeStamp的情况下.在这种情况下，您可以使用:

test_df['Date'].str.replace("-","").astype(int) Note that this won't work if your "Date" column is not a string object, typically when Pandas has already parsed your series as TimeStamp. In this case you can use :

test_df['Date'].dt.strftime("%Y%m%d").astype(int)

这篇关于 pandas :将日期"object"转换为int的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！