Python程序可计算列表中的正数和负数

2021年4月1日15:27:10 发表评论 951 次浏览

给定一个数字列表, 编写一个Python程序以计算列表中的正数和负数

例子:

Input: list1 = [2, -7, 5, -64, -14]
Output: pos = 2, neg = 3

Input: list2 = [-12, 14, 95, 3]
Output: pos = 3, neg = 1

范例1:使用for循环计算给定列表中的正数和负数

使用for循环遍历列表中的每个元素, 并检查num> = 0, 这是检查正数的条件。如果条件满足, 则增加pos_count, 否则增加neg_count。

# Python program to count positive and negative numbers in a List
  
# list of numbers
list1 = [ 10 , - 21 , 4 , - 45 , 66 , - 93 , 1 ]
  
pos_count, neg_count = 0 , 0
  
# iterating each number in list
for num in list1:
      
     # checking condition
     if num > = 0 :
         pos_count + = 1
  
     else :
         neg_count + = 1
          
print ( "Positive numbers in the list: " , pos_count)
print ( "Negative numbers in the list: " , neg_count)

输出如下:

Positive numbers in the list:  4
Negative numbers in the list:  3

范例2:使用while循环

# Python program to count positive and negative numbers in a List
  
# list of numbers
list1 = [ - 10 , - 21 , - 4 , - 45 , - 66 , 93 , 11 ]
  
pos_count, neg_count = 0 , 0
num = 0
  
# using while loop     
while (num < len (list1)):
      
     # checking condition
     if list1[num] > = 0 :
         pos_count + = 1
     else :
         neg_count + = 1
      
     # increment num 
     num + = 1
      
print ( "Positive numbers in the list: " , pos_count)
print ( "Negative numbers in the list: " , neg_count)

输出如下:

Positive numbers in the list:  2
Negative numbers in the list:  5

Example#3:使用Python Lambda表达式

# Python program to count positive
# and negative numbers in a List
  
# list of numbers
list1 = [ 10 , - 21 , - 4 , 45 , 66 , 93 , - 11 ]
  
neg_count = len ( list ( filter ( lambda x: (x < 0 ), list1)))
  
# we can also do len(list1) - neg_count
pos_count = len ( list ( filter ( lambda x: (x > = 0 ), list1)))
  
print ( "Positive numbers in the list: " , pos_count)
print ( "Negative numbers in the list: " , neg_count)

输出如下:

Positive numbers in the list:  4
Negative numbers in the list:  3

Example#4:使用清单理解

# Python program to count positive
# and negative numbers in a List
  
# list of numbers
list1 = [ - 10 , - 21 , - 4 , - 45 , - 66 , - 93 , 11 ]
  
only_pos = [num for num in list1 if num > = 1 ]
pos_count = len (only_pos)
  
print ( "Positive numbers in the list: " , pos_count)
print ( "Negative numbers in the list: " , len (list1) - pos_count)

输出如下:

Positive numbers in the list:  1
Negative numbers in the list:  6

首先, 你的面试准备可通过以下方式增强你的数据结构概念:Python DS课程。


木子山

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