character is changed, when converting

[Bill Wang]

When converting, why it changed the value false to False? (capital letter)

# cat a.j2
{
  "key": {
    "enabled": {{ app.enabled }}
}

# cat a.json
{
  "app": {
    "enabled": false
  }
}

# j2 a.j2 a.json
{
  "key": {
    "enabled": False
}

[Mark]

This is Python behavior: it's boolean literal has a capital F.

Use Jinja2 |lower filter: {{ bool_variable|str|lower }}