need strings function

[zhangguanzhang]

{% set my_string = "abc" %}

{{ my_string.startswith('a') }}
{{ my_string.endswith('c') }}
{{ my_string.upper() }}
{{ my_string.lower() }}
{{ my_string.replace('a', 'x') }}
{{ my_string.strip() }}
{{ my_string.split('b') }}

output

True
True
ABC
abc
xbc
abc
['a', 'c']

[zhangguanzhang]

github.com/nikolalohinski/gonja help me