Python将范围内的随机整数附加到列表中，计算数字的出现次数

Question

So I have the following code:

import random
from collections import Counter
L = []
for x in range(0, 100):
    L.append([])
    for y in range(0, 6):
        L[x].append(random.randint(0, 45) + 1)

Now I need to be able to count the number of times each number appears in the list. I tried counter and all kinds of other stuff, still get errors and I'm stuck. Any help would be appreciated.

Answer 1

You can store a per sublist Counter in a list and then sum all these counters.

I assume you want the count of each number across all sublists.

from collections import Counter
from functools import reduce
import random


L = []
counters = []

for _ in range(0, 100):
    sublist = []

    for y in range(0, 6):
        sublist.append(random.randint(0, 45) + 1)

    counters.append(Counter(sublist))
    L.append(sublist)


def counter_reducer(accumulator, next_item):
    return accumulator + next_item


counts = reduce(counter_reducer, counters, Counter())
print(counts)  # Counter({23: 20, 46: 19, 12: 19, ...})

Answer 2

If i understand your question right - You can create another list with the length of all your possible numbers, now every time that number appended you are adding 1 to the his corresponding index , say:

count_list = [0] * 47
L = []
for x in range(0, 100):
L.append([])
for y in range(0, 6):
    L[x].append(random.randint(0, 45) + 1)
    count_list[L[x][y]] += 1

now, every index in the coubt_list represent a number and inside him the number of appears

Answer 3

You can add a List contain the same elements as L and count them using count try this :

L = []
e = []
for x in range(0, 10):
    L.append([])
    for y in range(0, 3):
        a = random.randint(0, 45) + 1
        L[x].append(a)
        e.append(a)
for z in e :
print (z,e.count(z))

Answer 4

The easiest way to do this is to make use of the dictionary .get() method to increment values if they have been seen before, or start with a default count of 0.

my_count = {}
for lst in L:
    for item in lst:
        my_count[item] = my_count.get(item, 0) + 1

However, since you're already iterating in this way to create the list, you can do it all together:

import random

my_count = {}
L = []
for x in range(0, 100):
    L.append([])
    for y in range(0, 6):
        num = random.randint(0, 45) + 1
        L[x].append(num)
        my_count[num] = my_count.get(num, 0) + 1

Answer 5

You could use the histogram function from numpy:

import numpy as np 
import random
from collections import Counter
L = []
ll, lu = 0, 45 # set bounds for random samples
for x in range(0, 2):
    L.append([])
    for y in range(0, 3):
        L[x].append(random.randint(ll,lu) + 1)


bcen=np.linspace(ll, lu, lu+1) # centers
bed=np.linspace(ll-0.5, lu+0.5, lu+2) #edges
cnts, bed =np.histogram(L, bins=bed)

print('Random integers')
print(L)
print('Counts')
print(np.append(bcen.reshape(-1,1),cnts.reshape(-1,1), axis=1))

Note: I made your list smaller, just so that the print out is readable, but just adjust it as you wish.