筛选符合条件的数据

import pandas as pd
data = {'created_at':['a','a','a','b','c']}
df = pd.DataFrame.from_dict(data)
df['b'] = df['created_at']
df
# 选出某列不包含特定值的所有数据
df[ df['created_at'] != 'a']
# 选出某列包含特定值的所有数据
list1 = ['a','b']
df[df.loc[:, 'created_at'].isin(list1)]
# 选出某列不包含特定值列表的所有数据
list1 = ['a','b']
df[~df.loc[:, 'created_at'].isin(list1)]