Problem
Develop a list comprehension to transform the following string: split the string by space into a list, filter out the non-aphabetic characters, transform each word into its lower and also calculate the length of the word.
str1 = "The FIFA World Cup Qatar 2022 will be played from 20 November to 18 December."
Expected output: [('the', 3), ('fifa', 4), ('world', 5), ('cup', 3), ('qatar', 5), ('will', 4), ('be', 2), ('played', 6), ('from', 4), ('november', 8), ('to', 2),('december.', 9)]