extract data from date range (time & date format)

I have a date set for a couple of years and I am trying to extract data from a specific range and time, but I cannot get it to work with Pandas. I am sure there is something wrong with the date & time format, but oddly I can get hourly averages but cannot extract a date & time range.

This is the code, but it never return any data, I know it there is data in that time period. I think the date & time format is correct, but not sure why it does not work. Any help would be highly appreciated

Code

import pandas as pd

import numpy as np

df = pd.DataFrame([['2018-01-01 16:00:00+00:00', 2], ['2018-01- 
01 17:00:00+00:00', 3], ['2018-01-01 18:00:00+00:00', 6]['2018- 
01-01 19:00:00+00:00', 9]], columns=['time', 'data'])

print(df.head)

df['time'] = pd.to_datetime(df['time']) 

df2018 = df.loc['2018-01-01 16:30:00':'2018-01-01 18:00:00']

print(df2018.head)