"""
Exercise 4.2 from "A primer on...". The same
Fahrenheit-Celcius formula we used earlier, but
the Fahrenheit temperature should be read
as a command line argument.
"""
import sys

F = sys.argv[1]
F = float(F)

C = (F - 32) * 5 / 9
print(C)

"""
Terminal> f2c_cml.py 78
25.555555555555557
"""