[GIS] Getting list of QGIS field names, not including hidden fields using PyQGIS

pyqgispythonqgis

Currently, for a python plugin for QGIS 2.8.3, I get the list of fields for a layer using pendingFields as mentioned in this thread:

fields = self.layer.pendingFields()

I now have a few hidden fields (set via the fields tab in layer properties). How can I get a list of fields that are not hidden?

I see the possibility to get Edit Type, but am not sure where to go from here :

EditType { 
  LineEdit, UniqueValues, UniqueValuesEditable, ValueMap, 
  Classification, EditRange, SliderRange, CheckBox, 
  FileName, Enumeration, Immutable, Hidden, 
  TextEdit, Calendar, DialRange, ValueRelation, 
  UuidGenerator, Photo, WebView, Color, 
  EditorWidgetV2 
}

Best Answer

The vector layer object has a editorWidgetV2ByName method which allows you to pass in a field name and get back the the name of the Edit Widget as a string. For example:

>>> layer.editorWidgetV2ByName("fieldname")
'Hidden'

Alternately there is the editorWidgetV2 method which allows you to pass in a field index:

>>> layer.editorWidgetV2(0)
'Hidden'

The list of names for different widgets can be found with the documentation for setEditorWidgetV2, which incidently can be used to set the widget for a field given the index, like so:

>>> layer.setEditorWidgetV2(0, "Hidden")

So to get a list of fields which aren't hidden you can use the following snippet:

fields = [
    field for field in layer.pendingFields()
    if layer.editorWidgetV2ByName(field.name() != "Hidden")
]

Related Solutions

[GIS] Getting field names in PyQGIS

It is simpler than with version 1.8:

layer = qgis.utils.iface.activeLayer()  
fields = layer.pendingFields()   
field_names = [field.name() for field in fields]

or in one line

field_names = [field.name() for field in layer.pendingFields() ]

an after

for elem in layer.getFeatures():  
   print dict(zip(field_names, elem.attributes()))
{u'adip': 17, u'dipdir': 130, u'tdip': 29}
{u'adip': 55, u'dipdir': 325, u'tdip': 75}
.....

Generally to explore a new function, I use the dir() or the see module to examine what's inside:

dir(fields)
['FieldOrigin', 'OriginEdit', 'OriginJoin', 'OriginProvider', 'OriginUnknown', '__class__', '__delattr__', '__delitem__', '__dict__', '__doc__', '__format__', '__getattribute__', '__getitem__', '__hash__', '__init__', '__len__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', 'append', 'at', 'clear', 'count', 'extend', 'field', 'fieldOrigin', 'fieldOriginIndex', 'indexFromName', 'isEmpty', 'remove', 'size', 'toList']

see(fields)
[]                 hash()             help()             len()
repr()             str()              .FieldOrigin()     .OriginEdit
.OriginJoin        .OriginProvider    .OriginUnknown     .append()
.at()              .clear()           .count()           .extend()
.field()           .fieldOrigin()     .fieldOriginIndex()
.indexFromName()   .isEmpty()         .remove()          .size()
.toList()

And you can see that there is a field() function so

print fields.field(0)
qgis.core.QgsField object at 0x163E39C0

and a field has a name, a type, a precision,...:

see(fields.field(0))
<                 <=                ==                !=                >
>=                hash()            help()            repr()
str()             .comment()        .displayString()  .length()
.name()           .precision()      .setComment()     .setLength()
.setName()        .setPrecision()   .setType()        .setTypeName()
.type()           .typeName()

so:

fields.field(0).name()
u'adip'
fields.field(0).type()
2
fields.field(0).typeName()
u'Integer'
fields.field(0).precision()
0
....

with .dataProvider()

It is .field()

....
prov = layer.dataProvider()
prov.fields().field(0).name()
u'adip'
prov.fields().field(0).typeName()
u'Integer'

and

field_names = [field.name() for field in prov.fields()]

[GIS] Getting list of layers names using PyQGIS

Visible layers

You could use this function to get layer names printed:

def get_layers():
    # List visible layers (warning: only spatial ones)
    layer_list = []
    for layer in iface.mapCanvas().layers():
        item = layer.name()
        layer_list.append(item)
    print(layer_list)
    
get_layers()

Layers in TOC (layers panel / legend / layer tree)

In case that you need all layers in the TOC (not only those that are visible/checked, as mapCanvas().layers() returns), you can use this function:

def get_toc_layers(group):
    # List all layers in a group
    for child in group.children():
        if isinstance(child, QgsLayerTreeLayer):
            print(child.layer().name())
        else:
            get_toc_layers(child)

root = QgsProject.instance().layerTreeRoot()
get_toc_layers(root)

All registered layers

QGIS can use layers that are part of the QGIS project but are not shown in the TOC. If you want to get those layers listed as well, do this:

def get_all_layers():
    # List register layers (even if they aren't in the TOC)
    layer_list = []
    for k, layer in QgsProject.instance().mapLayers().items():
        layer_list.append(layer.name())
    
    print(layer_list)
    
get_all_layers()