The if and else statements can perform simple tests. For example:
# Compute the maximum (z) of a and b if a < b: z = b else: z = a
The bodies of the if and else clauses are denoted by indentation. The else clause is optional.
To create an empty clause, use the pass statement as follows:
if a < b: pass # Do nothing else: z = a
You can form Boolean expressions by using the or, and, and not keywords:
if b >= a and b <= c: print "b is between a and c" if not (b < a or b > c): print "b is still between a and c"
To handle multiple-test cases, use the elif statement, like this:
if a == '+': op = PLUS elif a == '-': op = MINUS elif a == '*': op = MULTIPLY else: raise RuntimeError, "Unknown operator"