Class: QgsFields¶
- class qgis.core.QgsFields¶
Bases:
sip.wrapper
Container of fields for a vector layer.
In addition to storing a list of
QgsField
instances, it also:allows quick lookups of field names to index in the list
keeps track of where the field definition comes from (vector data provider, joined layer or newly added from an editing operation)
Note
QgsFields
objects are implicitly shared.QgsFields() Constructor for an empty field container
QgsFields(other:
QgsFields
) Copy constructorMethods
Utility function to get list of attribute indexes
Appends a field.
Appends an expression field.
Returns the field at particular index (must be in range 0..N-1).
Removes all fields
Returns number of items
Returns if a field index is valid
Extends with fields from another
QgsFields
containerReturns the field at particular index (must be in range 0..N-1).
Returns the field's origin (value from an enumeration).
Returns the field's origin index (its meaning is specific to each type of origin).
Returns an icon corresponding to a field index, based on the field's type and source
Returns an icon corresponding to a field
type
Gets the field index from the field name.
Gets the field index from the field name.
Checks whether the container is empty
Looks up field's index from the field name.
Returns a list with field names
Removes the field with the given index.
Renames a name of field.
Returns number of items
Utility function to return a list of
QgsField
instancesAttributes
- class FieldOrigin¶
Bases:
int
- OriginEdit = 3¶
- OriginExpression = 4¶
- OriginJoin = 2¶
- OriginProvider = 1¶
- OriginUnknown = 0¶
- allAttributesList(self) List[int] ¶
Utility function to get list of attribute indexes
New in version 2.4.
- Return type:
List[int]
- append(self, field: QgsField, origin: QgsFields.FieldOrigin = QgsFields.OriginProvider, originIndex: int = -1) bool ¶
Appends a field. The field must have unique name, otherwise it is rejected (returns
False
)- Parameters:
field (QgsField) –
origin (QgsFields.FieldOrigin = QgsFields.OriginProvider) –
originIndex (int = -1) –
- Return type:
bool
- appendExpressionField(self, field: QgsField, originIndex: int) bool ¶
Appends an expression field. The field must have unique name, otherwise it is rejected (returns
False
)- Parameters:
field (QgsField) –
originIndex (int) –
- Return type:
bool
- at(self, i: int) QgsField ¶
Returns the field at particular index (must be in range 0..N-1).
- Raises:
KeyError – if no field exists at the specified index
- Parameters:
i (int) –
- Return type:
- clear(self)¶
Removes all fields
- count(self) int ¶
Returns number of items
- Return type:
int
- exists(self, i: int) bool ¶
Returns if a field index is valid
- Parameters:
i (int) – Index of the field which needs to be checked
- Return type:
bool
- Returns:
True
if the field exists
- extend(self, other: QgsFields)¶
Extends with fields from another
QgsFields
container- Parameters:
other (QgsFields) –
- field(self, fieldIdx: int) QgsField ¶
Returns the field at particular index (must be in range 0..N-1).
- Raises:
KeyError – if no field exists at the specified index
field(self, name: str) -> QgsField Returns the field with matching name.
- Raises:
KeyError – if no matching field was found.
- Parameters:
fieldIdx (int) –
- Return type:
- fieldOrigin(self, fieldIdx: int) QgsFields.FieldOrigin ¶
Returns the field’s origin (value from an enumeration).
- Raises:
KeyError – if no field exists at the specified index
- Parameters:
fieldIdx (int) –
- Return type:
- fieldOriginIndex(self, fieldIdx: int) int ¶
Returns the field’s origin index (its meaning is specific to each type of origin).
- Raises:
KeyError – if no field exists at the specified index
- Parameters:
fieldIdx (int) –
- Return type:
int
- iconForField(self, fieldIdx: int, considerOrigin: bool = False) QIcon ¶
Returns an icon corresponding to a field index, based on the field’s type and source
- Parameters:
fieldIdx (int) – the field index
considerOrigin (bool = False) – if
True
the icon will the origin of the field
- Raises:
KeyError – if no field exists at the specified index
New in version 2.14.
- Return type:
QIcon
- iconForFieldType(type: QVariant.Type) QIcon ¶
Returns an icon corresponding to a field
type
New in version 3.16.
- Parameters:
type (QVariant.Type) –
- Return type:
QIcon
- indexFromName(self, fieldName: str) int ¶
Gets the field index from the field name.
This method is case sensitive and only matches the data source name of the field.
Alias for indexOf
- Parameters:
fieldName (str) – The name of the field.
- Return type:
int
- Returns:
The field index if found or -1 in case it cannot be found.
See also
- indexOf(self, fieldName: str) int ¶
Gets the field index from the field name.
This method is case sensitive and only matches the data source name of the field.
- Parameters:
fieldName (str) – The name of the field.
- Return type:
int
- Returns:
The field index if found or -1 in case it cannot be found.
See also
New in version 3.0.
- isEmpty(self) bool ¶
Checks whether the container is empty
- Return type:
bool
- lookupField(self, fieldName: str) int ¶
Looks up field’s index from the field name. This method matches in the following order:
The exact field name taking case sensitivity into account
Looks for the field name by case insensitive comparison
The field alias (case insensitive)
- Parameters:
fieldName (str) – The name to look for.
- Return type:
int
- Returns:
The field index if found or -1 in case it cannot be found.
See also
New in version 2.4.
- names(self) List[str] ¶
Returns a list with field names
New in version 3.0.
- Return type:
List[str]
- remove(self, fieldIdx: int)¶
Removes the field with the given index.
- Raises:
KeyError – if no field with the specified index exists
- Parameters:
fieldIdx (int) –
- rename(self, fieldIdx: int, name: str) bool ¶
Renames a name of field. The field must have unique name, otherwise change is rejected (returns
False
)New in version 3.6.
- Parameters:
fieldIdx (int) –
name (str) –
- Return type:
bool
- size(self) int ¶
Returns number of items
- Return type:
int