Factorization of use statements.
-rw-r--r-- 29 .gitignore
drwxr-xr-x - ch2-str-simple-pattern
drwxr-xr-x - ch4-cubsat-ground-station
drwxr-xr-x - ch5-data-in-depth
drwxr-xr-x - ch6-memory
drwxr-xr-x - ch7-file-and-storage