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.
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