python--- 统计列表中每个数据值出现的次数并组织成字典展示
目录
1. for 循环
2. for循环方法2:
3. 利用内置函数Counter
4. 利用函数
eg: l1 = ['yietong','yietong','kevin','oscar']
结果:{'yietong':2,'kevin':1,'oscar':1}
真实数据
l1 = ['yietong','yietong','kevin','oscar','kevin','tony','kevin']
提供以下四种方法:
1. for 循环
建一个空字典, 循环打印列表,根据列表中元素出现的次数计数, 转换成字典格式.
l1 = ['yietong','yietong','kevin','oscar','kevin','tony','kevin']
dict = {}
for i in l1:
if i not in dict:
dict[i] = 1
else:
dict[i] += 1
print(dict) # {'yietong': 2, 'kevin': 3, 'oscar': 1, 'tony': 1}2. for循环方法2:
先将列表转换成集合,在统计列表中元素出现的次数.
l1 = ['yietong','yietong','kevin','oscar','kevin','tony','kevin']
l = {}
for i in set(l1)
l[i] = l1.count(i)
print(l)
# {'yietong': 2, 'tony': 1, 'kevin': 3, 'oscar': 1}
3. 利用内置函数Counter
引用模块,最简便快速的方式
l1 = ['yietong','yietong','kevin','oscar','kevin','tony','kevin']
from collections import Counter
l = Counter(l1)
print(l) # Counter({'kevin': 3, 'yietong': 2, 'oscar': 1, 'tony': 1})4. 利用函数
for循环时将列表数据类型转换成集合(字典格式会报错),统计元素出现次数.
执行函数,将结果作为返回值return出去
l1 = ['yietong','yietong','kevin','oscar','kevin','tony','kevin']
def list(l1):
l = {}
for i in set(l1):
l[i] = l1.count(i)
return l
print(list(l1)) # {'oscar': 1, 'yietong': 2, 'kevin': 3, 'tony': 1}
此方法是基于方法2之上的进阶版.