Context Manager

Context managers are used to allocate and release some sort of resource when you need it.

The best know use case is file access:

with open("test.txt", "w") as fh:

fh.write("Πάλι βρέχει στο Λονδίνο,\n")

fh.write("Κι έχει ζέστη στην Ελλάδα\n")

with open("test.txt") as fh:

for line in fh:

print(line)