How do you count positive numbers in python?

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

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Method: Using enumerate function
Method : Using startswith() method
How do you find positive values in Python?
How do you count positive and negative numbers in an array in Python?
How do you count negative numbers in a list in Python?
How do you sum all positive numbers in Python?

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.

Python3

list1 = [10, -21, 4, -45, 66, -93, 1]

pos_count, neg_count = 0, 0

for num in list1:

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

Python3

list1 = [-10, -21, -4, -45, -66, 93, 11]

pos_count, neg_count = 0, 0

num = 0

while(num < len(list1)):

if list1[num] >= 0:

pos_count += 1

else:

neg_count += 1

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

Python3

list1 = [10, -21, -4, 45, 66, 93, -11]

neg_count = len(list(filter(lambda x: (x < 0), list1)))

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

Python3

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

Method: Using enumerate function

Python3

l=[12, -7, 5, 64, -14];c=0

x=[a for j,a in enumerate(l) if a>=0]

print("Length of Positive numbers is:", len(x))

print("Length of Nagetive numbers is:", len(l)-len(x))

Output

Length of Positive numbers is: 3
Length of Nagetive numbers is: 2

Method : Using startswith() method

Python3

list1 = [10, -21, 4, -45, 66, -93, 1,0]

pos_count, neg_count = 0, 0

list2=list(map(str,list1))

for num in list2:

if num.startswith("-"):

neg_count += 1

elif(num!="0"):

if(not num.startswith("-")):

pos_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

How do you find positive values in Python?

The abs() function is used to get the absolute (positive) value of a given number. The argument may be an integer or a floating point number. If the argument is a complex number, its magnitude is returned.

How do you count positive and negative numbers in an array in Python?

Approach 1 − Brute-force approach using iteration construct(for) Here we need to iterate each element in the list using a for loop and check whether num>=0, to filter the positive numbers. If the condition evaluates to be true, then increase pos_count otherwise, increase neg_count.

How do you count negative numbers in a list in Python?

Inside the Python for loop, we are using the If statement to check and count Positive and Negative numbers. if(NumList[1] >= 0) => if(-22 >= 0) – Condition is False, so it enters the Else block. if(5 >= 0) – Condition is True.