Dada una lista de números, escriba un programa en Python para contar números positivos y negativos en una lista.
Ejemplo:
Input: list1 = [2, -7, 5, -64, -14] Output: pos = 2, neg = 3 Input: list2 = [-12, 14, 95, 3] Output: pos = 3, neg = 1
Ejemplo #1: Cuente números positivos y negativos de una lista dada usando el ciclo for
Itere cada elemento de la lista usando for loop y verifique si num >= 0, la condición para verificar números positivos. Si la condición se cumple, aumente pos_count; de lo contrario, aumente 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)
Producción:
Positive numbers in the list: 4 Negative numbers in the list: 3
Ejemplo #2: Usando el ciclo while
# 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)
Producción:
Positive numbers in the list: 2 Negative numbers in the list: 5
Ejemplo n.º 3: uso de expresiones lambda de Python
# 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)
Producción:
Positive numbers in the list: 4 Negative numbers in the list: 3
Ejemplo #4: Uso de la comprensión de listas
# 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)
Producción:
Positive numbers in the list: 1 Negative numbers in the list: 6