统计列表中各元素出现的次数

count.py

def count(lst):
    r = {}
    for i in lst:
        if i in r:
            r[i] += 1
        else:
            r[i] = 1
    return r


if __name__ == '__main__':
    assert count([1,1,2,2,3,4]) == {1:2, 2:2, 3:1, 4:1}
    assert count([1,1,'a','a']) == {1:2, 'a':2}
    assert count([1]) == {1:1}
    assert count([]) == {}
    assert count(['ab','ab','bc']) == {'ab':2, 'bc':1}
    print('Well Done!')