Python|运算符.countOf

Operator.countOf()用于计算b在a中出现的次数。它计算 value 出现的次数。

Syntax : Operator.countOf(freq = a, value = b)
Parameters :
freq : It can be list or any other data type which store value
value : It is value for which we have to count the number of occurrences

Returns: Count of number of occurrences of value.

示例 #1：使用Operator.countOf()计算列表中给定值的出现次数。

# Python program showing
# use of countOf() function
# in a list
  
from operator import * 
arr = [ 1, 2, 3, 3, 3 ]
arr1 = [ 'a', 'b', 'c', 'b', 'd' ]
  
print("Number of occurrence of b in arr1 =", countOf(arr1, "b"))
print("Number of occurrence of e in arr1 =", countOf(arr1, "e"))
print("Number of occurrence of 3 in arr =", countOf(arr, 3))

输出：

Number of occurrence of b in arr1 = 2
Number of occurrence of e in arr1 = 0
Number of occurrence of 3 in arr = 3

示例 #2：使用Operator.countOf()计算字典中给定值的出现次数。

# Python program showing
# use of countOf() function
# in a dictionary
  
from operator import *
  
d = {"score": 3, "score1": 1, "score2": 3, "score3": 1, "score4": 3}
  
print("Number of occurrence of three in dict =",countOf(d.values(),3))
print("Number of occurrence of one in dict =",countOf(d.values(),1))
print("Number of occurrence of four in dict =",countOf(d.values(),4))

输出 ：

Number of occurrence of three in dict = 3
Number of occurrence of one in dict = 2
Number of occurrence of four in dict = 0

示例 #3：使用Operator.countOf()计算元组中给定值的出现次数。

# Python program showing
# use of countOf() function
# in a tuples
  
from operator import *
   
tup = ( 1, 2, 3, 3, 3 )
tup1 = ( 'a', 'b', 'c', 'b', 'd' )
   
print("Number of occurrence of b in tuple1 =",countOf(tup1,"b"))
print("Number of occurrence of e in tuple1 =",countOf(tup1,"e"))
print("Number of occurrence of 3 in tuple =",countOf(tup,3))

输出 ：

Number of occurrence of b in tuple1 = 2
Number of occurrence of e in tuple1 = 0
Number of occurrence of 3 in tuple = 3