14.3) Exercise 38 - Bradford Weather

For this exercise, you’ll need to download the following file:
bradforddata.txt
This file (bradforddata.txt) contains data from the Bradford weather station. It consists of:

• Mean daily maximum temperature (tmax)
• Mean daily minimum temperature (tmin)
• Days of air frost (af)
• Total rainfall (rain)
• Total sunshine duration (sun)

Missing data (more than two days missing in a month) have been indicated by "---".

1. Read in weather data from Bradford station. Skip the header rows and specify the string used to represent missing values.
2. Calculate the mean temperature for each month (tmean) as the average of tmax and tmin.

Solution: np_exercise_bradford_data.py
To go further: write the monthly mean temperature of Bradford to a file.