python | 统计频次

def get_counts(sequence):
    counts = {}
    for x in sequence:
        if x in counts:
            counts[x] += 1
        else:
            counts[x] = 1
    return counts

from collections import defaultdict

def get_counts2(sequence):
    counts = defaultdict(int) 
    for x in sequence:
        counts[x] += 1
    return counts

tz_counts = frame['tz'].value_counts()
tz_counts[:10]

def check(x,L):
    if x in L:
        return True
    else:
        L.append(x)

def top_counts(count_dict, n):
    value_key_pairs = [(count, tz) for tz, count in count_dict.items()]
    value_key_pairs.sort()
    return value_key_pairs[-n:]

from collections import Counter
counts = Counter(time_zones)
counts.most_common(n)