我如何在熊猫身上确定年龄和约会

Question

这是我的数据

Customer_id    Date-of-birth
1              1992-07-02
2              1991-07-03

这是我的代码

import datetime as dt
df['now'] = dt.datetime.now()
df['age'] = df['now'].dt.date - df['Date-of-birth']

这是的结果

Customer_id    Date-of-birth     age
1              1992-07-02        xxxx days
2              1991-07-03        xxxx days

我想要的结果是

Customer_id    Date-of-birth     age
1              1992-07-02        26 years 22 days
2              1991-07-03        27 years 21 days

现在让您知道，根据df.dtypes，Date-of-birth是一个对象，因为它基于下拉中的客户输入

我怎样才能做到这一点？我希望这个问题足够清楚

Answer 1

将此解决方案与自定义功能一起使用，因为计数并不容易，因为跨越了几年：

from dateutil.relativedelta import relativedelta
def f(end):
r = relativedelta(pd.to_datetime('now'), end) 
return '{} years {} days'.format(r.years, r.days)
df['age'] = df["Date-of-birth"].apply(f)
print (df)
Customer_id Date-of-birth               age
0            1    1992-07-02  26 years 22 days
1            2    1991-07-03  27 years 21 days

Answer 2

输入：

import pandas as pd
import datetime as dt
now = dt.datetime.now()
for i in range(0, len(df)):
diff = now - dt.datetime.strptime(df['Date-of-Birth'][i], '%Y-%m-%d')
years = diff.days // 365
days = diff.days - (years*365)
df['age'][i] = str(years) + ' years ' + str(days) + ' days'
print(df)

输出：

Customer_id     Date-of-Birth          age
1            1992-07-04       26 years 25 days
2            1991-07-04       27 years 26 days

Answer 3

也许您可以使用以下内容。请注意，它依赖于平均每年有365.25天的事实，因此有时可能会休息一天。

import datetime as dt
def year_days_diff(x):
diff = (dt.datetime.now() - x).days
return str(int(diff / 365.25)) + ' years ' + str(int(diff / 365.25 % 1 * 365.25)) + ' days'

示例：

birth_date = dt.datetime.now() - dt.timedelta(10000)
year_days_diff(birth_date)

输出：

'27 years 138 days'

Answer 4

这可以通过四舍五入到年来确定年龄。

ref_date = dt.datetime.now()
df['age'] = df['Date-of-birth'].apply(lambda x: len(pd.date_range(start = x, end = ref_date, freq = 'Y'))) 

Answer 5

使用astype('<m8[Y]')

例如：

df['age'] = (pd.to_datetime('now') - df['Date-of-birth']).astype('<m8[Y]')

演示：

import pandas as pd
df = pd.DataFrame({"Date-of-birth": pd.to_datetime(['1992-07-24', '1991-07-24'])})
df["age"] = (pd.to_datetime('now') - df["Date-of-birth"]).astype('<m8[Y]')
print(df)

输出：

Date-of-birth   age
0    1992-07-24  25.0
1    1991-07-24  27.0