f-strings everywhere

docs/patterns/flashing.rst

@@ -103,7 +103,7 @@ error messages could be displayed with a red background.
 To flash a message with a different category, just use the second argument
 to the :func:`~flask.flash` function::
 
-    flash(u'Invalid password provided', 'error')
+    flash('Invalid password provided', 'error')
 
 Inside the template you then have to tell the
 :func:`~flask.get_flashed_messages` function to also return the

docs/patterns/lazyloading.rst

@@ -93,7 +93,7 @@ write this by having a function that calls into
 name and a dot, and by wrapping `view_func` in a `LazyView` as needed.  ::
 
     def url(import_name, url_rules=[], **options):
-        view = LazyView('yourapplication.' + import_name)
+        view = LazyView(f"yourapplication.{import_name}")
         for url_rule in url_rules:
             app.add_url_rule(url_rule, view_func=view, **options)
 

docs/patterns/requestchecksum.rst

@@ -52,4 +52,4 @@ Example usage::
         files = request.files
         # At this point the hash is fully constructed.
         checksum = hash.hexdigest()
-        return 'Hash was: %s' % checksum
+        return f"Hash was: {checksum}"

docs/patterns/sqlalchemy.rst

@@ -104,9 +104,9 @@ You can insert entries into the database like this:
 Querying is simple as well:
 
 >>> User.query.all()
-[<User u'admin'>]
+[<User 'admin'>]
 >>> User.query.filter(User.name == 'admin').first()
-<User u'admin'>
+<User 'admin'>
 
 .. _SQLAlchemy: https://www.sqlalchemy.org/
 .. _declarative:
@@ -200,19 +200,19 @@ SQLAlchemy will automatically commit for us.
 To query your database, you use the engine directly or use a connection:
 
 >>> users.select(users.c.id == 1).execute().first()
-(1, u'admin', u'admin@localhost')
+(1, 'admin', 'admin@localhost')
 
 These results are also dict-like tuples:
 
 >>> r = users.select(users.c.id == 1).execute().first()
 >>> r['name']
-u'admin'
+'admin'
 
 You can also pass strings of SQL statements to the
 :meth:`~sqlalchemy.engine.base.Connection.execute` method:
 
 >>> engine.execute('select * from users where id = :1', [1]).first()
-(1, u'admin', u'admin@localhost')
+(1, 'admin', 'admin@localhost')
 
 For more information about SQLAlchemy, head over to the
 `website <https://www.sqlalchemy.org/>`_.

docs/patterns/streaming.rst

@@ -21,7 +21,7 @@ data and to then invoke that function and pass it to a response object::
     def generate_large_csv():
         def generate():
             for row in iter_all_rows():
-                yield ','.join(row) + '\n'
+                yield f"{','.join(row)}\n"
         return Response(generate(), mimetype='text/csv')
 
 Each ``yield`` expression is directly sent to the browser.  Note though

docs/patterns/viewdecorators.rst

@@ -142,8 +142,7 @@ Here is the code for that decorator::
             def decorated_function(*args, **kwargs):
                 template_name = template
                 if template_name is None:
-                    template_name = request.endpoint \
-                        .replace('.', '/') + '.html'
+                    template_name = f"'{request.endpoint.replace('.', '/')}.html'"
                 ctx = f(*args, **kwargs)
                 if ctx is None:
                     ctx = {}