def _column_value_getter(self, obj):
"""Create callable that returns column values for given object types."""
if is_namedtuple(obj):
# Get values using properties
def get(obj, column):
return getattr(obj, column, None)
elif is_dict_like(obj):
# Get values using dictionary keys
def get(obj, column):
return obj.get(column)
elif is_list_like(obj):
# Get values using list indexes
def get(obj, column):
col = self.column_location(column)
try:
return obj[col]
except IndexError:
return None
else:
# Fallback to single column
def get(obj, _):
return obj
return get
def _column_name_getter(self, obj):
"""Create callable that returns column names for given obj types."""
if is_namedtuple(obj):
# Use namedtuple fields as columns
def get(obj):
return list(obj._fields)
elif is_dict_like(obj):
# Use dictionary keys as columns
def get(obj):
return list(obj.keys())
elif is_list_like(obj):
# Use either predefined columns, or
# generate range-based column values
predefined = list(self._columns)
def get(obj):
count = len(obj)
if predefined:
if count > len(predefined):
raise ValueError(
f"Data had more than defined {count} columns")
return predefined[:count]
else:
return list(range(count))
else:
# Fallback to single column
def get(_):
return self._columns[:1] if self._columns else [0]
return get