寻找缺失的数据

Aim:to find the different data between 2 columns!

import numpy as np
import pandas as pd
import matplotlib as mpl

import os
import math
import glob
import datetime

transform=lambda x:x.to_pydatetime().replace(microsecond=0)
transform2=lambda x:x.to_pydatetime().replace(second=0)

dm=[]

path=r'E:\Check_met_fnl.xlsx'
df=pd.read_excel(path,sheet_name='Mea',header=0,parse_dates=True, usecols=['date_time','real_time'])
df['date_time']=df['date_time'].map(transform)
df['date_time']=df['date_time'].map(transform2)

for i in np.arange(len(df['real_time'])):
    temp=df['real_time'][i]
    
    if any(df['date_time'].isin([temp])):
        print(i)
    else :
          dm.append(temp)    ### Find the different data!