add missing test module docstrings, correct imports

pyformlang/cfg/tests/test_recursive_decent_parser.py

@@ -1,12 +1,12 @@
-# pylint: disable=missing-module-docstring
-# pylint: disable=missing-class-docstring
-# pylint: disable=missing-function-docstring
+"""Tests for recursive top-down parser."""
+
+import pytest
+
 from pyformlang.cfg import CFG, Variable, Terminal
 from pyformlang.cfg.recursive_decent_parser import (
     RecursiveDecentParser,
     NotParsableError,
 )
-import pytest
 
 
 @pytest.fixture

pyformlang/fcfg/tests/test_fcfg.py

@@ -1,4 +1,6 @@
-"""Test a FCFG."""
+"""Tests for FCFG."""
+
+import pytest
 
 from pyformlang.cfg import Variable, Terminal, Production
 from pyformlang.cfg import DerivationDoesNotExistError
@@ -8,7 +10,6 @@
 from pyformlang.fcfg.feature_production import FeatureProduction
 from pyformlang.fcfg.feature_structure import FeatureStructure
 from pyformlang.fcfg.state import State, StateProcessed
-import pytest
 
 
 @pytest.fixture

pyformlang/fcfg/tests/test_feature_structure.py

@@ -1,12 +1,13 @@
 """Testing of the feature structure."""
 
+import pytest
+
 from pyformlang.fcfg.feature_structure import (
     FeatureStructure,
     PathDoesNotExistError,
     ContentAlreadyExistsError,
     FeatureStructuresNotCompatibleError,
 )
-import pytest
 
 
 def _get_agreement_subject_number_person():

pyformlang/pda/tests/test_pda.py

@@ -1,8 +1,9 @@
 """Tests the PDA."""
 
-import pytest
 from os import path
 
+import pytest
+
 from pyformlang.pda import PDA, State, StackSymbol, Symbol, Epsilon
 from pyformlang.cfg import Terminal, Epsilon as CFGEpsilon
 from pyformlang.finite_automaton import DeterministicFiniteAutomaton