List comprehensions in Python. Translation from book "Programming Haskell" examples. Erik Meijer Functional Programming class on Edx.

list_comp_misc.py

pairs = lambda xs: zip(xs, xs[1:])
print pairs([1,2,3,4,5,6]) # [(1, 2), (2, 3), (3, 4), (4, 5), (5, 6)]

sorted = lambda xs: all([x<=y for (x, y) in pairs(xs)])
print sorted([1,2,3,4,5,6,7]) # True
print sorted([1,2,3,4,5,9,7]) # False

list_comp_primes.py

print "- Factors of an integer- "
factors = lambda n: [ x for x in range(1,n+1) if n % x == 0 ]
x = 15
print "Factors of %d: %r" % (x, factors(x))
x = 7
print "Factors of %d: %r\n" % (x, factors(x))

print "- Is a number a prime? -"
prime = lambda n: factors(n) == [1,n]
x = 15
print "Is %d a prime? %r" % (x, prime(x))
x = 7
print "Is %d a prime? %r\n" % (x, prime(x))

print "- List all the primes less than a given number -"
primes = lambda n: [ x for x in range(2, n+1) if prime(x) ]
x = 7
print "Primes up to %d: %r" % (x, primes(x))
x = 40
print "Primes up to %d: %r" % (x, primes(x))