Convert pandas dataframe column with string array (Python)

Question

I have a data frame pandas in Python, in which one of the columns is bringing the values in an array(list). I would like to remove the brackets ([]), to convert into string. I have tried with strip, regex and nothing.

It’s like this:

I’d like to keep it that way:

Answer 1

You can use the pandas applymap together with isinstance:

df.applymap(lambda x: x if not isinstance(x, list) else " ".join(x))

The data frame receives the value of x without modifications if it is not a list, if a list makes a concatenation of the elements. Works for empty list.

Answer 2

A way that worked properly and gets very fast was:

df['liststring'] = df['lists'].apply(lambda x: x[1:-1])

The new column liststring receives the string of the existing list in df['lists'].