Python中的过滤器列表项

Question

我需要从城市列表中删除不超过5个字符的城市名称：

下面的代码可以工作，但我觉得代码太长了，应该有另一个方法可以用来缩短代码的长度。

cities = ["New York", "Shanghai", "Munich", "Tokyo", "Dubai", "Mexico 
City", "São Paulo", "Hyderabad"]
count = 0
loop = 0

print("City List:",cities)

for x in range(len(cities)):
    if len(cities[x]) <= 5:
        cities[x] = 'small'

for x in range(len(cities)):
    if cities[x] == 'small':
        count += 1

while loop < count:
    for x in cities:
        if x == 'small':
            cities.remove(x)
            loop += 1

print("Filtered:",cities)

Answer 1

最短的方法是列表理解。

cities = [city for city in cityes if len(city) < 6]

这等同于

cities_filterd = []
for city in cities:
    if len(city) < 6:
        cities_filterd.append(city)

然后，cities_filterd将包含长度小于6的citiey。

Answer 2

您可以使用filter：

filtered_cities = list(filter(lambda x: len(x) > 5, cities)