根据if-elif-else条件创建新列时出错

时间:2020-09-02 08:26:13

标签: python pandas numpy jupyter-notebook

我正在尝试创建一个新列并将其添加为dataframe的Week。另外,我正在根据其他条件进行此操作。我在下面使用代码。

 # List of the conditions
conditions = [
    (df_sup[(df_sup['Date']>='2016-11-14') & (df_sup['Date']<'2016-11-21')]),
    (df_sup[(df_sup['Date']>='2016-11-21') & (df_sup['Date']<'2016-11-28')]), 
    (df_sup[(df_sup['Date']>='2016-11-28') & (df_sup['Date']<'2016-12-05')]), 
    (df_sup[(df_sup['Date']>='2016-12-05') & (df_sup['Date']<'2016-12-12')]),
    (df_sup[(df_sup['Date']>='2016-12-12') & (df_sup['Date']<'2016-12-19')])
]


# list of the values I want to assign for each condition
values = ['week1','week2','week3','week4','week5']

# Let's create a new column and use np.select to assign values to it using our lists as arguments
df_sup['Week'] = np.select(conditions, values)

但是,我遇到了以下错误。我该如何解决?

enter image description here

此外,我在下面共享数据。

enter image description here

1 个答案:

答案 0 :(得分:1)

您的数据conditions中不是条件列表,因为已使用boolean indexing,所以请获取数据帧列表。

因此,对于条件列表,请删除df_sup[,最后删除]

conditions = [
    (df_sup['Date']>='2016-11-14') & (df_sup['Date']<'2016-11-21'),
    (df_sup['Date']>='2016-11-21') & (df_sup['Date']<'2016-11-28'), 
    (df_sup['Date']>='2016-11-28') & (df_sup['Date']<'2016-12-05'), 
    (df_sup['Date']>='2016-12-05') & (df_sup['Date']<'2016-12-12'),
    (df_sup['Date']>='2016-12-12') & (df_sup['Date']<'2016-12-19')
]