def __init__(self, sql_ctx, schema, modifier=None):
    self.sql_ctx = sql_ctx
    self.schema = schema
    self.modifier = modifier
    self._columns = [_DataFrameColumn(self, f, i) for (i, f) in enumerate(schema.fields)]
    self._name_to_column_map = {f.name: c for (f, c) in zip(schema.fields, self._columns)}
def __init__(self, sql_ctx, schema, modifier=None):
    self.sql_ctx = sql_ctx
    self.schema = schema
    self.modifier = modifier
    self._columns = [_DataFrameColumn(self, f, i) for (i, f) in enumerate(schema.fields)]
    self._name_to_column_map = {f.name: c for (f, c) in zip(schema.fields, self._columns)}