Python program to count positive and negative numbers in a list

Given a list of numbers, write a Python program to count positive and negative numbers in a List.

Example:

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

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

Example #1: Count positive and negative numbers from given list using for loop

Iterate each element in the list using for loop and check if num >= 0, the condition to check positive numbers. If the condition satisfies, then increase pos_count else increase 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) 

Output:

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

Example #2: Using while loop

# 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) 

Output:

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

Example #3 : Using Python Lambda Expressions

# 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) 

Output:

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

Example #4 : Using List Comprehension

# 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) 

Output:

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

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