How to read lines from compressed text files in Python

Question

Is it easy to read a line from a gz-compressed text file using python without extracting the file completely?

My requirement is that I have a text.gz file which is around 300Mb. When I extract it, it becomes 8gb. I have to read 10 files in total. 

How can it be done using python? My requirement is that I need to read a text file line-by-line.

Appreciate the help!