diff --git a/tests/book.py b/tests/book.py
index 30cda5e..2417b6c 100644
--- a/tests/book.py
+++ b/tests/book.py
@@ -568,8 +568,10 @@ class CbInvTestCase(object):
                 self.assertEqual(book2.quantity, Decimal('20.0'))
                 self.assertEqual(book2.quantity_all, Decimal('20.0'))
                 # usd --> chf: 1750 US$ * 0.95 / 1.05 = 1583.333 €
-                # 1 ounce --> 20 gram: 1583.333 CHF * 20 / 28.3495 = 1117.0097 CHF
-                self.assertEqual(book2.current_value, Decimal('1117.01'))   # CHF
+                # 1 ounce --> 20 gram:
+                #   1583.333 CHF * 20 / 28.3495 = 1117.0097 CHF
+                self.assertEqual(
+                    book2.current_value, Decimal('1117.01'))   # CHF
                 self.assertEqual(
                     book2.current_value_ref, Decimal('1175.80'))   # EUR
                 self.assertEqual(book2.diff_amount, Decimal('-132.99'))
@@ -698,7 +700,8 @@ class CbInvTestCase(object):
                 }])
             self.assertEqual(
                 books[1].lines[1].rec_name,
-                '05/01/2022|from|1.00 usd|- [Book 1 | 1.00 usd | Open | 1.000 u]')
+                '05/01/2022|from|1.00 usd|- [Book 1 | ' +
+                '1.00 usd | Open | 1.000 u]')
             self.assertEqual(books[1].lines[1].quantity_digits, 3)
 
     @with_transaction()
@@ -736,7 +739,8 @@ class CbInvTestCase(object):
                 }])
 
             self.assertEqual(book.name, 'Book 1')
-            self.assertEqual(book.rec_name, 'Book 1 | 0.00 usd | Open | 0.0000 u')
+            self.assertEqual(
+                book.rec_name, 'Book 1 | 0.00 usd | Open | 0.0000 u')
             self.assertEqual(book.btype.rec_name, 'A - Asset')
             self.assertEqual(book.state, 'open')
             self.assertEqual(book.feature, 'asset')
@@ -845,7 +849,8 @@ class CbInvTestCase(object):
                 }])
 
             self.prep_category(cattype='in')
-            category_out = self.prep_category(name='Out Category', cattype='out')
+            category_out = self.prep_category(
+                name='Out Category', cattype='out')
             self.prep_party()
 
             asset = self.prep_asset_item(
@@ -1008,7 +1013,8 @@ class CbInvTestCase(object):
                     'feature': 'asset',
                 }])
 
-            category_out = self.prep_category(name='Out Category', cattype='out')
+            category_out = self.prep_category(
+                name='Out Category', cattype='out')
             self.prep_party()
 
             asset = self.prep_asset_item(
@@ -1099,7 +1105,8 @@ class CbInvTestCase(object):
                 }])
 
             self.prep_category(cattype='in')
-            category_out = self.prep_category(name='Out Category', cattype='out')
+            category_out = self.prep_category(
+                name='Out Category', cattype='out')
             self.prep_party()
 
             asset = self.prep_asset_item(
@@ -1239,7 +1246,8 @@ class CbInvTestCase(object):
                 }])
 
             self.prep_category(cattype='in')
-            category_out = self.prep_category(name='Out Category', cattype='out')
+            category_out = self.prep_category(
+                name='Out Category', cattype='out')
             self.prep_party()
 
             asset = self.prep_asset_item(
@@ -1384,7 +1392,8 @@ class CbInvTestCase(object):
                 }])
 
             self.prep_category(cattype='in')
-            category_out = self.prep_category(name='Out Category', cattype='out')
+            category_out = self.prep_category(
+                name='Out Category', cattype='out')
             self.prep_party()
 
             asset1 = self.prep_asset_item(
@@ -1572,7 +1581,8 @@ class CbInvTestCase(object):
                 }])
 
             self.prep_category(cattype='in')
-            category_out = self.prep_category(name='Out Category', cattype='out')
+            category_out = self.prep_category(
+                name='Out Category', cattype='out')
             self.prep_party()
 
             asset1 = self.prep_asset_item(
@@ -1632,7 +1642,8 @@ class CbInvTestCase(object):
 
             self.assertRaisesRegex(
                 UserError,
-                r'Cannot transfer quantities between cashbooks with different unit-categories \(Time != Weight\).',
+                r'Cannot transfer quantities between cashbooks with ' +
+                r'different unit-categories \(Time != Weight\).',
                 Book.write,
                 *[
                     [book],
@@ -1707,7 +1718,8 @@ class CbInvTestCase(object):
                         }])],
                 }])
 
-            self.assertEqual(book.rec_name, 'Book 1 | 11.00 usd | Open | 4.00 u')
+            self.assertEqual(
+                book.rec_name, 'Book 1 | 11.00 usd | Open | 4.00 u')
             self.assertEqual(book.balance_all, Decimal('11.0'))
             self.assertEqual(len(book.lines), 1)
 
@@ -1722,10 +1734,12 @@ class CbInvTestCase(object):
             self.assertEqual(len(book.lines[0].splitlines), 2)
             self.assertEqual(book.lines[0].splitlines[0].splittype, 'cat')
             self.assertEqual(book.lines[0].splitlines[0].amount, Decimal('5.0'))
-            self.assertEqual(book.lines[0].splitlines[0].quantity, Decimal('1.5'))
+            self.assertEqual(
+                book.lines[0].splitlines[0].quantity, Decimal('1.5'))
             self.assertEqual(book.lines[0].splitlines[1].splittype, 'cat')
             self.assertEqual(book.lines[0].splitlines[1].amount, Decimal('6.0'))
-            self.assertEqual(book.lines[0].splitlines[1].quantity, Decimal('2.5'))
+            self.assertEqual(
+                book.lines[0].splitlines[1].quantity, Decimal('2.5'))
 
     @with_transaction()
     def test_assetbook_split_in_category_and_assetbook(self):
@@ -1813,7 +1827,8 @@ class CbInvTestCase(object):
 
             self.assertEqual(len(books[0].lines[0].splitlines), 2)
             self.assertEqual(books[0].lines[0].splitlines[0].splittype, 'cat')
-            self.assertEqual(books[0].lines[0].splitlines[0].amount, Decimal('5.0'))
+            self.assertEqual(
+                books[0].lines[0].splitlines[0].amount, Decimal('5.0'))
             self.assertEqual(
                 books[0].lines[0].splitlines[0].quantity,
                 Decimal('1.5'))
@@ -1822,7 +1837,8 @@ class CbInvTestCase(object):
                 'Cat1')
             self.assertEqual(books[0].lines[0].splitlines[0].booktransf, None)
             self.assertEqual(books[0].lines[0].splitlines[1].splittype, 'tr')
-            self.assertEqual(books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
+            self.assertEqual(
+                books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
             self.assertEqual(
                 books[0].lines[0].splitlines[1].quantity,
                 Decimal('2.5'))
@@ -1832,7 +1848,8 @@ class CbInvTestCase(object):
             self.assertEqual(len(books[0].lines[0].references), 0)
             self.assertEqual(books[0].lines[0].reference, None)
 
-            self.assertEqual(books[1].rec_name, 'Book 2 | 0.00 usd | Open | 0.00 u')
+            self.assertEqual(
+                books[1].rec_name, 'Book 2 | 0.00 usd | Open | 0.00 u')
             self.assertEqual(books[1].balance_all, Decimal('0.0'))
             self.assertEqual(len(books[1].lines), 0)
 
@@ -1854,7 +1871,8 @@ class CbInvTestCase(object):
 
             self.assertEqual(len(books[0].lines[0].splitlines), 2)
             self.assertEqual(books[0].lines[0].splitlines[0].splittype, 'cat')
-            self.assertEqual(books[0].lines[0].splitlines[0].amount, Decimal('5.0'))
+            self.assertEqual(
+                books[0].lines[0].splitlines[0].amount, Decimal('5.0'))
             self.assertEqual(
                 books[0].lines[0].splitlines[0].quantity,
                 Decimal('1.5'))
@@ -1863,7 +1881,8 @@ class CbInvTestCase(object):
                 'Cat1')
             self.assertEqual(books[0].lines[0].splitlines[0].booktransf, None)
             self.assertEqual(books[0].lines[0].splitlines[1].splittype, 'tr')
-            self.assertEqual(books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
+            self.assertEqual(
+                books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
             self.assertEqual(
                 books[0].lines[0].splitlines[1].quantity,
                 Decimal('2.5'))
@@ -1984,7 +2003,8 @@ class CbInvTestCase(object):
             self.assertEqual(len(books[0].lines[0].references), 0)
             self.assertEqual(books[0].lines[0].reference, None)
 
-            self.assertEqual(books[1].rec_name, 'Book 2 | 0.00 usd | Open | 0.00 u')
+            self.assertEqual(
+                books[1].rec_name, 'Book 2 | 0.00 usd | Open | 0.00 u')
             self.assertEqual(books[1].balance_all, Decimal('0.0'))
             self.assertEqual(len(books[1].lines), 0)
 
@@ -2268,7 +2288,8 @@ class CbInvTestCase(object):
             self.assertEqual(
                 asset1.rec_name,
                 'Aurum | 1,750.0000 usd/oz | 05/01/2022')
-            self.assertEqual(asset2.rec_name, 'Liquid | 10.0000 usd/l | 05/01/2022')
+            self.assertEqual(
+                asset2.rec_name, 'Liquid | 10.0000 usd/l | 05/01/2022')
 
             (usd, euro) = self.prep_2nd_currency(company)
             self.assertEqual(company.currency.rec_name, 'Euro')
@@ -2309,7 +2330,8 @@ class CbInvTestCase(object):
 
             self.assertRaisesRegex(
                 UserError,
-                r"Cannot transfer quantities between cashbooks with different unit-categories \(Weight != Volume\).",
+                r"Cannot transfer quantities between cashbooks with " +
+                r"different unit-categories \(Weight != Volume\).",
                 Book.write,
                 *[
                     [books[0]],
@@ -2392,7 +2414,8 @@ class CbInvTestCase(object):
                         }])],
                 }])
 
-            self.assertEqual(book.rec_name, 'Book 1 | -11.00 usd | Open | -4.00 u')
+            self.assertEqual(
+                book.rec_name, 'Book 1 | -11.00 usd | Open | -4.00 u')
             self.assertEqual(book.balance_all, Decimal('-11.0'))
             self.assertEqual(len(book.lines), 1)
             self.assertEqual(book.lines[0].splitline_has_quantity, False)
@@ -2501,7 +2524,8 @@ class CbInvTestCase(object):
             self.assertEqual(len(books[0].lines[0].references), 0)
             self.assertEqual(books[0].lines[0].reference, None)
 
-            self.assertEqual(books[1].rec_name, 'Book 2 | 0.00 usd | Open | 0.00 u')
+            self.assertEqual(
+                books[1].rec_name, 'Book 2 | 0.00 usd | Open | 0.00 u')
             self.assertEqual(books[1].balance_all, Decimal('0.0'))
             self.assertEqual(len(books[1].lines), 0)
 
@@ -2526,7 +2550,8 @@ class CbInvTestCase(object):
                 books[0].lines[0].splitlines[1].rec_name,
                 'Exp/Sp|6.00 usd|to cashbook [Book 2 | 6.00 usd | Open' +
                 ' | 2.50 u]|2.50 u')
-            self.assertEqual(books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
+            self.assertEqual(
+                books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
             self.assertEqual(
                 books[0].lines[0].splitlines[1].amount_2nd_currency,
                 None)
@@ -2544,7 +2569,8 @@ class CbInvTestCase(object):
                 ' | Open | -4.00 u]|2.50 u')
             self.assertEqual(books[0].lines[0].reference, None)
 
-            self.assertEqual(books[1].rec_name, 'Book 2 | 6.00 usd | Open | 2.50 u')
+            self.assertEqual(
+                books[1].rec_name, 'Book 2 | 6.00 usd | Open | 2.50 u')
             self.assertEqual(books[1].balance_all, Decimal('6.0'))
             self.assertEqual(len(books[1].lines), 1)
             self.assertEqual(
@@ -2641,7 +2667,8 @@ class CbInvTestCase(object):
                 books[0].lines[0].splitlines[0].rec_name,
                 'Exp/Sp|5.00 usd|to category [Cat1]')
             self.assertEqual(books[0].lines[0].splitlines[0].quantity, None)
-            self.assertEqual(books[0].lines[0].splitlines[0].quantity_2nd_uom, None)
+            self.assertEqual(
+                books[0].lines[0].splitlines[0].quantity_2nd_uom, None)
             self.assertEqual(
                 books[0].lines[0].splitlines[1].rec_name,
                 'Exp/Sp|6.00 usd|to cashbook [Book Asset | 0.00 usd | ' +
@@ -2649,7 +2676,8 @@ class CbInvTestCase(object):
             self.assertEqual(
                 books[0].lines[0].splitlines[1].quantity,
                 Decimal('2.5'))
-            self.assertEqual(books[0].lines[0].splitlines[1].quantity_2nd_uom, None)
+            self.assertEqual(
+                books[0].lines[0].splitlines[1].quantity_2nd_uom, None)
 
             self.assertEqual(len(books[0].lines[0].references), 0)
             self.assertEqual(books[0].lines[0].reference, None)
@@ -2683,7 +2711,8 @@ class CbInvTestCase(object):
                 books[0].lines[0].splitlines[1].rec_name,
                 'Exp/Sp|6.00 usd|to cashbook [Book Asset | 6.00 usd' +
                 ' | Open | 2.50 u]')
-            self.assertEqual(books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
+            self.assertEqual(
+                books[0].lines[0].splitlines[1].amount, Decimal('6.0'))
             self.assertEqual(
                 books[0].lines[0].splitlines[1].amount_2nd_currency,
                 None)
@@ -2992,7 +3021,8 @@ class CbInvTestCase(object):
 
             self.assertRaisesRegex(
                 UserError,
-                r"Cannot transfer quantities between cashbooks with different unit-categories \(Weight != Volume\).",
+                r"Cannot transfer quantities between cashbooks with " +
+                r"different unit-categories \(Weight != Volume\).",
                 Book.write,
                 *[
                     [books[0]],