Were you ever in the desperate need to know all primes below 1000?

In Python calculating primes can be done with a one-liner using functional programming concepts lambda function, map(), reduce() and filter():

# Primes <1000
print filter(None,map(lambda y:y*reduce(lambda x,y:x*y!=0,map(lambda x,y=y: y%x, range(2,int(pow(y,0.5)+1))),1), range(2, 1000)))&#91;/sourcecode&#93;

To try this out on a system with python installed in a terminal/console/... type python. In the command prompt showing up paste the line, hit enter and you'll get:
<code>[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997]</code>Update: Thanks to <a href="http://wordpress.com/blog/2007/09/03/posting-source-code/">Matt</a> and <a href="http://en.forums.wordpress.com/topic.php?id=6435&amp;page&amp;replies=9#post-111641">Mark</a> the code snippet now can look much <a href="http://faq.wordpress.com/2007/09/03/how-do-i-post-source-code/">nicer</a>:


# Primes <1000
print filter(None, map(lambda y: y*reduce(lambda x,y: x*y!=0, map(lambda x,y=y: y%x, range(2, int(pow(y, 0.5)+1))),1),range(2,1000)))&#91;/sourcecode&#93;

Update: Not quite as accurate (compare start of the sequence, 3 is missing) but <a href="http://www.python.org/doc/current/tut/node7.html#SECTION007130000000000000000">much shorter</a> using another formula and filter() and lambda techniques only:


filter(lambda x: x % 2 != 0 and x % 3 != 0, range(2, 1000))

[5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997]