Pandas Series: str.join() function

Series-str.join() function

The str.join() function is used to Join lists contained as elements in the Series/Index with passed delimiter.

If the elements of a Series are lists themselves, join the content of these lists using the delimiter passed to the function. This function is an equivalent to str.join().

Syntax:

Series.str.join(self, sep)

Parameters:

Returns: Series/Index: object
The list entries concatenated by intervening occurrences of the delimiter.

Raises: AttributeError
If the supplied Series contains neither strings nor lists.

Notes:If any of the list items is not a string object, the result of the join will be NaN

Example - Example with a list that contains non-string elements:

Python-Pandas Code:

import numpy as np
import pandas as pd
s = pd.Series([['tiger', 'lion', 'deer'],
              [2.2, 3.3, 4.4],
              ['fox', np.nan, 'cat'],
              ['camel', 5.5, 'monkey'],
              ['duck', ['swan', 'fish'], 'guppy']])
s

Output:

0            [tiger, lion, deer]
1                [2.2, 3.3, 4.4]
2                [fox, nan, cat]
3           [camel, 5.5, monkey]
4    [duck, [swan, fish], guppy]
dtype: object

Example - Join all lists using a ‘-‘. The lists containing object(s) of types other than str will produce a NaN:

Python-Pandas Code:

import numpy as np
import pandas as pd
s = pd.Series([['tiger', 'lion', 'deer'],
              [2.2, 3.3, 4.4],
              ['fox', np.nan, 'cat'],
              ['camel', 5.5, 'monkey'],
              ['duck', ['swan', 'fish'], 'guppy']])
s.str.join('-')

Output:

0    tiger-lion-deer
1                NaN
2                NaN
3                NaN
4                NaN
dtype: object

Previous: Series-str.get() function
Next: Series-str.len() function