一文搞定统计字符串中某字符出现的频次

rlt = {}

for i in content:

    if i in rlt.keys():

        rlt[i] += 1

    else:

        rlt[i] = 1

rlt = {}

for i in content:

    if i not in rlt.keys():

        rlt[i] = content.count(i)

rlt = {}

for i in content:

    rlt.setdefault(i,content.count(i))

Python 字典 setdefault() 函数和 get()方法 类似, 如果键不存在于字典中，将会添加键并将值设为默认值。