Lambdas Python for loop

Question

I wanted to use lambdas inside for loops to return if certain elements are non-numerical:

strs = ['1234', 'hello', '6787']

I can use a for loop and iterate through each element:

for elem in strs:

and check elem.islpha().

However, is there a way to use lambdas coupled with a for loop to return the word "hello"?

Answer 1

Try this, it's easy using a list comprehension:

lst =  ['1234', 'hello', '6787']
[x for x in lst if x.isalpha()]
=>  ['hello']

Or if you definitely want to use a lambda:

filter(lambda x: x.isalpha(), lst)
=>  ['hello']

Notice that you'll rarely use lambdas for filtering inside a for loop, it's not idiomatic. The way to go for filtering elements out of a list is using list comprehensions, generator expressions or (less recommended) the filter() built-in function.