diff --git a/python/plugins/processing/algs/gdal/gdaltindex.py b/python/plugins/processing/algs/gdal/gdaltindex.py
index 546f707f8aa..81a9cdb6f46 100644
--- a/python/plugins/processing/algs/gdal/gdaltindex.py
+++ b/python/plugins/processing/algs/gdal/gdaltindex.py
@@ -150,7 +150,7 @@ class gdaltindex(GdalAlgorithm):
             arguments.append('-src_srs_name {}'.format(crs_field))
 
         if crs_format:
-            arguments.append('-src_srs_format {}'.format(self.modes[crs_format][1]))
+            arguments.append('-src_srs_format {}'.format(self.formats[crs_format][1]))
 
         if target_crs.isValid():
             arguments.append('-t_srs')
diff --git a/python/plugins/processing/algs/grass7/Grass7Algorithm.py b/python/plugins/processing/algs/grass7/Grass7Algorithm.py
index 11f738b2232..19b37e30d3e 100644
--- a/python/plugins/processing/algs/grass7/Grass7Algorithm.py
+++ b/python/plugins/processing/algs/grass7/Grass7Algorithm.py
@@ -738,7 +738,7 @@ class Grass7Algorithm(QgsProcessingAlgorithm):
         :param colorTable: preserve color Table.
         :param outFormat: file format for export.
         :param createOpt: creation options for format.
-        :param metatOpt: metadata options for export.
+        :param metaOpt: metadata options for export.
         """
         if not createOpt:
             if outFormat in Grass7Utils.GRASS_RASTER_FORMATS_CREATEOPTS:
diff --git a/python/plugins/processing/algs/qgis/DefineProjection.py b/python/plugins/processing/algs/qgis/DefineProjection.py
index 4c7d46aa51d..7e7cf364dc6 100644
--- a/python/plugins/processing/algs/qgis/DefineProjection.py
+++ b/python/plugins/processing/algs/qgis/DefineProjection.py
@@ -90,7 +90,7 @@ class DefineProjection(QgisAlgorithm):
                 with open(qpjFile, 'w') as f:
                     f.write(wkt)
         else:
-            feedback.pushConsoleInfo(tr("Data source isn't a shapefile, skipping .prj/.qpj creation"))
+            feedback.pushConsoleInfo(self.tr("Data source isn't a shapefile, skipping .prj/.qpj creation"))
 
         layer.setCrs(crs)
         layer.triggerRepaint()
diff --git a/python/plugins/processing/algs/qgis/FieldsMapper.py b/python/plugins/processing/algs/qgis/FieldsMapper.py
index 8bc357a3407..47f0ad25cf3 100644
--- a/python/plugins/processing/algs/qgis/FieldsMapper.py
+++ b/python/plugins/processing/algs/qgis/FieldsMapper.py
@@ -82,7 +82,7 @@ class FieldsMapper(QgisFeatureBasedAlgorithm):
     def prepareAlgorithm(self, parameters, context, feedback):
         source = self.parameterAsSource(parameters, 'INPUT', context)
         if source is None:
-            raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
+            raise QgsProcessingException(self.invalidSourceError(parameters, 'INPUT'))
 
         mapping = self.parameterAsFieldsMapping(parameters, self.FIELDS_MAPPING, context)
 
diff --git a/python/plugins/processing/algs/qgis/RectanglesOvalsDiamondsVariable.py b/python/plugins/processing/algs/qgis/RectanglesOvalsDiamondsVariable.py
index ec2e845233b..649ddcecb7e 100644
--- a/python/plugins/processing/algs/qgis/RectanglesOvalsDiamondsVariable.py
+++ b/python/plugins/processing/algs/qgis/RectanglesOvalsDiamondsVariable.py
@@ -27,6 +27,7 @@ __revision__ = '$Format:%H$'
 
 import math
 
+from qgis.PyQt.QtCore import QCoreApplication
 from qgis.core import (QgsWkbTypes,
                        QgsFeature,
                        QgsFeatureSink,