Python-сообщество

 list(zip(*np.unique(text, return_counts=True)))

 #include <iostream>
#include <iomanip>
using namespace std;
const int N=100000000;
const int M=256;
static unsigned char arr[N];
int main()
{
    int count[M]={0};
    int i;
    for(i=0;i<N;++i){arr[i]=i;}
    for(i=0;i<N;++i){++count[arr[i]];}
    for(i=0;i<M;++i)
    {
        cout<<count[i]<<endl;
    }
    cout<<"done"<<endl;
    return 0;
}

 text = np.random.choice(list(alphabet.keys()), p=list(alphabet.values()), size=length)

 import random
import numpy as np
def create_text(length):
    alphabet = {str(i-1): np.float64(i / 55.0) for i in range(1, 11)}
    return np.random.choice(list(alphabet.keys()), p=list(alphabet.values()), size=length)
text = create_text(100000000)
text, len(text)

 def f_prev(text):
    l1 = np.unique(text, return_counts=True)
    l2 = zip(*l1)
    l3 = {code: count for code, count in l2}
    return l3

 def f_view(text):
    l1 = np.unique(text.view(np.int), return_counts=True)
    l2 = zip(*l1)
    l3 = {chr(code): count for code, count in l2}
    return l3

 f_prev(text)

 f_prev(text) == f_view(text)

 %%timeit -n 5
f_prev(text)

 %%timeit -n 5
f_view(text)

 %%cython -a 
#cython: boundscheck=False
import numpy as np
cimport numpy as np
cpdef trivial1_cyth1(text):
    cdef int[:] text_int_view = text.view(np.int)
    cdef int[:] c = np.zeros(256, dtype=np.int)
    cdef int l = len(text_int_view )
    cdef int i
    for i in range(l):
        c[text_int_view [i]] += 1
    return {chr(i): c[i] for i in range(len(c)) if c[i] > 0}

 text, len(text)

 %%timeit
trivial1_cyth1(text)

 def f_prev(text):
    l1 = np.unique(text, return_counts=True)
    l2 = zip(*l1)
    l3 = {code: count for code, count in l2}
    return l3

 %%timeit -n 5
f_prev(text)

 res = trivial1_cyth1(text)
res_prev = f_prev(text)
res == res_prev