The challenge
Count the number of occurrences of each character and return it as a list of tuples in order of appearance. For empty output return an empty list.
Example:
ordered_count("abracadabra") == [('a', 5), ('b', 2), ('r', 2), ('c', 1), ('d', 1)]
The solution in Python code
Option 1:
from collections import Counter
def ordered_count(input):
c = Counter(input)
return sorted(list(c.items()), key=lambda x: input.index(x[0]))
Option 2:
def ordered_count(_input):
l = []
for i in _input:
if i not in l:
l.append(i)
return [(i, _input.count(i)) for i in l]
Option 3:
def ordered_count(inp):
return [(i, inp.count(i)) for i in sorted(set(inp), key=inp.index)]
Test cases to validate our solution
test.describe("Basic Tests")
tests = (
('abracadabra', [('a', 5), ('b', 2), ('r', 2), ('c', 1), ('d', 1)])
)
for t in tests:
inp, exp = t
test.assert_equals(ordered_count(inp), exp)
test.describe("Random Tests")
def random_tests():
from string import (
ascii_letters,
punctuation,
digits
)
from collections import (
OrderedDict,
Counter
)
from random import (
randint,
choice
)
class _OrderedCounter(Counter, OrderedDict):
pass
def reference(seq):
return list(_OrderedCounter(seq).items())
CHARS = "".join((" ", ascii_letters, punctuation, digits))
for _ in range(100):
test_case = "".join(choice(CHARS) for _ in range(randint(1, 1000)))
test.assert_equals(ordered_count(test_case), reference(test_case))
random_tests()
