如何從列表中刪除少於N個令牌的字符串？

Question

給出一個字符串列表，說：

a = ['hey','hey how are you','good how are you','I am', 'I am fine 8998','9809 908']

如何刪除少於三個令牌的字符串？：

a = ['hey how are you','good how are you', 'I am fine 8998']

我試過了：

' '.join(a.split(' ')[3:])

但是，它不起作用。 知道如何刪除少於三個令牌的所有字符串

Answer 1

你可以使用這個列表理解：

>>> [i for i in a if len(i.split())>=3]
['hey how are you', 'good how are you', 'I am fine 8998']

Answer 2

這是使用filter和lambda執行相同操作的另一種方法：

a = ['hey','hey how are you','good how are you','I am', 'I am fine 8998','9809 908']

res = list(filter(lambda x: x.count(' ') >= 2, a))
# ['hey how are you', 'good how are you', 'I am fine 8998']

要么：

res = list(filter(lambda x: len(x.split()) >= 3, a))