I am trying to change an plugin from QGIS 1.8 to 2.0. In the 1.8 version I create a table of the field names like this:
layer = vlayer
provider = layer.dataProvider()
feat = QGSFeatrue()
allAttrs = provider.attributeIndexes()
provider.select(allAttrs)
fieldNames = []
while provider.nextFeature(feat)
fields = layer.pendingFields()
for (k, field) in fields.iteritems():
fieldNames.append(field.name())
I tried this for the 2.0 version with
layer = vlayer
fieldNames = []
for feature in layer.getFeatures():
fields = layer.pendingFields()
for (k, field) in fields.iteritems():
fieldNames.append(field.name())
But pendingFields() does not work for me. Is there now a new method to get the names of the fields?
Answer
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']
or
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
....
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()]
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