题解 | #牛客网用户练习的平均次日留存率#

import pandas as pd

pd.set_option("display.max_columns", None)  # 显示所有的列，而不是以……显示
pd.set_option("display.max_rows", None)  # 显示所有的行，而不是以……显示
pd.set_option("display.width", None)  # 不自动换行显示

df = pd.read_csv("nowcoder.csv")
df['date'] = pd.to_datetime(df.date).dt.date
df1 = df.copy()

df1['date'] = df1['date'] + pd.Timedelta(days=1)
totle = pd.merge(df,df1,how='inner',on=['user_id','date'])

n = totle['user_id'].count()
n1 = df['user_id'].count()

print(round(n / n1,2))



# df = pd.read_csv('nowcoder.csv',sep=',')
# df['date'] = pd.to_datetime(df['date']).dt.date
# df1 = df.copy()

# df1['date'] = df1['date'] + pd.Timedelta(days=1)
# total = pd.merge(df,df1,how='inner',on=['user_id','date'])
 
# n = total['user_id'].count()
# n1 = df['user_id'].count()
 
# print(round(n / n1 ,2))