Python 3.x Python3基于其他列的变量创建列

我有一个数据集，包含一周中的年、月和日。但是，它缺少当月的实际日期（即从第1天到第30天）。数据集如下所示：

#   Year    Month   Day_Of_Week
22024   2002    January Tuesday
22101   2002    January Wednesday
22146   2002    January Thursday
22201   2002    January Friday
22247   2002    January Saturday
22280   2002    January Sunday
22335   2002    January Monday
22383   2002    January Tuesday
22384   2002    January Wednesday
22424   2002    January Thursday
22459   2002    January Friday
22511   2002    January Saturday
22598   2002    January Sunday
22599   2002    January Monday
22686   2002    January Tuesday
22687   2002    January Wednesday
22688   2002    January Wednesday
22689   2002    January Wednesday
22761   2002    January Wednesday
22762   2002    January Wednesday
22763   2002    January Wednesday
22764   2002    January Wednesday
22765   2002    January Thursday
22766   2002    January Thursday
22767   2002    January Thursday
22768   2002    January Thursday
22814   2002    January Friday
22815   2002    January Friday
22816   2002    January Friday
22817   2002    January Friday
22818   2002    January Friday

找到这一天的逻辑很简单。表中的第一条记录是第1天的。第二个记录是第2天，每当“周中的天”从上一个记录更改时，我们都会增加天数。 当月份是“一月”时，我们计算31天，“二月”则计算28天，以此类推

使用熊猫，我想创建一个名为“Crash_Day”的新专栏。如何迭代记录并按照上面的逻辑在新列中填充记录

如何构造for循环来读取每列的记录并相应地填充新列

这是到目前为止我的代码

import pandas as pd

crash_data = pd.read_csv('data.csv')
print('Length: {} rows.'.format(len(crash_data)))
print(crash_data.head())

如果有人有兴趣查看数据，请访问以下链接：

---

如果所有日期都是连续的，并且它们之间没有缺失，则可以使用lambda函数对每个连续值的开始使用（

！=

）比较ed值，然后用于

计数器

：

df['day'] = (df.groupby(['Year','Month'])['Day_Of_Week']
               .transform(lambda x: x.ne(x.shift()).cumsum()))

替代解决方案：

s = df['Day_Of_Week'].ne(df['Day_Of_Week'].shift())
df['day'] = s.groupby([df['Year'],df['Month']]).cumsum().astype(int)

---

---

我要做的是把你的“每周一天”专栏拿出来，和它自己比较一下，但换了一个。然后，无论什么地方不同，都是它在几天内发生变化。如果你在不同的地方写一个新的列，如1和0，那么你可以得到该列的累计和，这将计算所有的天数（不断增加）。然后，您可以找出如何将该列（如[0，0，0，1，1，…，31，31，32，32，33，…）转换为在月份正确包装（实际上，可以对月份执行完全相同的操作来重置计数器…）而不是说上述方法特别有效。我只是对《熊猫》中的约会内容做得还不够好，无法给出更好的答案：）非常感谢你来拜访亚历山大。下面的代码成功了；）你真了不起，耶斯雷尔，非常感谢你的帮助

print (df)
       Year     Month Day_Of_Week  day
22024  2002   January     Tuesday    1
22101  2002   January   Wednesday    2
22146  2002   January    Thursday    3
22201  2002   January      Friday    4
22247  2002   January    Saturday    5
22280  2002   January      Sunday    6
22335  2002   January      Monday    7
22383  2002   January     Tuesday    8
22384  2002   January   Wednesday    9
22424  2002   January    Thursday   10
22459  2002   January      Friday   11
22511  2002   January    Saturday   12
22598  2002   January      Sunday   13
22599  2002   January      Monday   14
22686  2002   January     Tuesday   15
22687  2002   January   Wednesday   16
22688  2002   January   Wednesday   16
22689  2002   January   Wednesday   16
22761  2002   January   Wednesday   16
22762  2002   January   Wednesday   16
22763  2002   January   Wednesday   16
22764  2002   January   Wednesday   16
22765  2002   January    Thursday   17
22766  2002   January    Thursday   17
22767  2002   January    Thursday   17
22768  2002   January    Thursday   17
22814  2002   January      Friday   18
22815  2002   January      Friday   18
22816  2002   January      Friday   18
22817  2002   January      Friday   18
22818  2002   January      Friday   18
22817  2002  February   Wednesday    1
22818  2002  February   Wednesday    1