您可以在 lambda function 中添加条件吗？

Question

I have the following code:

clean_tweets['tweet'] = clean_tweets['tweet'].apply(lambda x: remove_noise(x))

I want to add the logic add the condition that remove_noise is done only if the tweet is string

Is it possible to achieve this, are there any alternative ways of getting this done?

Answer 1

Yes, you can use a so-called ternary expression in Python, such as:

(result_if_clause_is_true) if (clause) else (result_if_clause_is_false)

In your specific case:

lambda x: remove_noise(x) if isinstance(x, str) else x

Anything more complex than an if/else operation should become its own function, however.

Note that this expression can be used in many other places, not only in lambdas:

x = y**2 if y < 10 else y/2  # assignment

Answer 2

• lambda x: remove_noise(x) is just remove_noise

• You should probably add the logic into remove_noise function:

   def remove_noise(x): if not isinstance(x, str): return x # or None or whatever other value # handle the case where x is a string

As a whole:

def remove_noise(x):
    if not isinstance(x, str):
        return x # or None or whatever othe value
    # handle the case where x is a string

clean_tweets['tweet'] = clean_tweets['tweet'].apply(remove_noise)