Le portail francophone de la géomatique

from qgis.utils import iface
from PyQt5.QtCore import QVariant

_CHAMP_NOM = 'NOM'
_CHAMP_SURFACE = 'SURFACE'
_VALEUR_CHERCHEE = 22

layer = iface.activeLayer()

# Create a dictionary of all features
feature_dict = {f.id(): f for f in layer.getFeatures()}

# Build a spatial index
index = QgsSpatialIndex()
for f in feature_dict.values():
    index.insertFeature(f)
    
# Loop through all features and find features that touch each feature
for f in feature_dict.values():
    geom = f.geometry()
    intersecting_ids = index.intersects(geom.boundingBox())
    for intersecting_id in intersecting_ids:
        # Look up the feature from the dictionary
        intersecting_f = feature_dict[intersecting_id]
        if (f != intersecting_f and
            not intersecting_f.geometry().disjoint(geom)):
                if (float(intersecting_f[_CHAMP_SURFACE]) + float(f[_CHAMP_SURFACE])) == _VALEUR_CHERCHEE:
                    print(intersecting_f[_CHAMP_NOM] + ' et ' + f[_CHAMP_NOM] + ' ont la somme de surface recherchée')