Python / Strings / Consonants
vowels = ("aeiou")
count = 0
for x in text:
    if not x in vowels:
        count += 1

consonants = "bcdfghjklmnpqrstvwxyz"
count = 0
for x in text:
    if x in consonants:
        count += 1

import string

all_letters = string.ascii_letters

consonants = set(all_letters).difference(set(('a','e','i','o','u','A','E','I','O','U')))

my_sentence = 'Here is my Sentence'

sum_of_cons = sum(ele in consonants for ele in my_sentence)

>>> sum_of_cons
10

consonants = set("bcdfghjklmnpqrstvwxyz")
count = sum(1 for c in text if c in consonants)

consonants = list("bcdfghjklmnpqrstvwxyz")
word=" hello world "
number_of_consonants = sum(word.count(c) for c in consonants)

Found 8292 Consonants in 0.002978 seconds using compiled regex
Found 8292 Consonants in 0.009412 seconds using sets
Found 8292 Consonants in 0.024511 seconds by looking at each character

import re
import time
import os
string_length = 100000
random_string = os.urandom(string_length)

con_re = re.compile("[bcdfghjklmnpqrstvwxyz]")
start = time.clock()
re_results = con_re.findall(random_string)
print "Found %d Consonants in %f seconds using compiled regex" % (len(re_results), time.clock() - start)

consonants = set("bcdfghjklmnpqrstvwxyz")
start = time.clock()
count = sum(1 for c in random_string if c in consonants)
print "Found %d Consonants in %f seconds using sets" % (count, time.clock() - start)

cnt = 0
consonants = "bcdfghjklmnpqrstvwxyz"
start = time.clock()
for x in range(string_length):
    if random_string[x] in consonants:
        cnt += 1
print "Found %d Consonants in %f seconds by looking at each character" % (cnt, time.clock() - start)