Refactoring Code

## [Setup.py](setup.py)

- Use `with` when opening file to ensure closure

## [Util.py](mako/util.py)

- Remove unnecessary else after guard condition
- Replace if statement with if expression
- Remove unnecessary else after guard condition
- Replace unneeded comprehension with generator
- Inline variable that is immediately returned

## [Template.py](mako/template.py)

- Replace if statement with if expression, Simplify if expression by using or
- Replace list(), dict() or set() with comprehension
- Swap if/else branches, Merge else clause's nested if statement into elif

## [Runtime.py](mako/runtime.py)

- Remove unnecessary else after guard condition

## [PyParser.py](mako/pyparser.py)

- Replace yield inside for loop with yield from
- Lift code into else after jump in control flow, Merge else clause's nested if statement into elif
- Replace if statement with if expression

## [Pygen.py](mako/pygen.py)

- Merge nested if conditions
- Simplify conditional into return statement (removes comment)
- Replace if statement with if expression, Simplify boolean if expression

## [Parsetree.py](mako/parsetree.py)

- Replace unneeded comprehension with generator
- Merge else clause's nested if statement into elif
- Replace unneeded comprehension with generator

## [Lookup.py](mako/lookup.py)

- Swap if/else branches, Merge else clause's nested if statement into elif
- Swap if/else branches, Remove unnecessary else after guard condition

## [Lexer.py](mako/lexer.py)

- Replace if statement with if expression
- Merge nested if conditions
- Swap if/else branches, Remove unnecessary else after guard condition, Merge else clause's nested if statement into elif
- Swap if/else branches, Remove unnecessary else after guard condition

## [Exceptions.py](mako/exceptions.py)

- Replace if statement with if expression, Use `with` when opening file to ensure closure

## [Ast.py](mako/ast.py)

- Replace multiple comparisons of same variable with `in` operator

## [Pygmentplugin.py](mako/ext/pygmentplugin.py)

- Replace if statement with if expression

Closes: #335
Pull-request: https://github.com/sqlalchemy/mako/pull/335
Pull-request-sha: c6243b116441f4b14e1cff00f47ed72aee3d3133

Change-Id: I9093e2f5ca4bb59aa12536b1a0bdf2d58514aa40

1 files changed, 90 insertions, 102 deletions

diff --git a/mako/lexer.py b/mako/lexer.py
index 74fafa1..306ae4b 100644
--- a/mako/lexer.py
+++ b/mako/lexer.py
@@ -54,10 +54,7 @@ class Lexer:
         try:
             reg = _regexp_cache[(regexp, flags)]
         except KeyError:
-            if flags:
-                reg = re.compile(regexp, flags)
-            else:
-                reg = re.compile(regexp)
+            reg = re.compile(regexp, flags) if flags else re.compile(regexp)
             _regexp_cache[(regexp, flags)] = reg
 
         return self.match_reg(reg)
@@ -75,10 +72,7 @@ class Lexer:
         match = reg.match(self.text, self.match_position)
         if match:
             (start, end) = match.span()
-            if end == start:
-                self.match_position = end + 1
-            else:
-                self.match_position = end
+            self.match_position = end + 1 if end == start else end
             self.matched_lineno = self.lineno
             lines = re.findall(r"\n", self.text[mp : self.match_position])
             cp = mp - 1
@@ -86,10 +80,6 @@ class Lexer:
                 cp -= 1
             self.matched_charpos = mp - cp
             self.lineno += len(lines)
-            # print "MATCHED:", match.group(0), "LINE START:",
-            # self.matched_lineno, "LINE END:", self.lineno
-        # print "MATCH:", regexp, "\n", self.text[mp : mp + 15], \
-        #          (match and "TRUE" or "FALSE")
         return match
 
     def parse_until_text(self, watch_nesting, *text):
@@ -149,12 +139,15 @@ class Lexer:
         if self.control_line:
             control_frame = self.control_line[-1]
             control_frame.nodes.append(node)
-            if not (
-                isinstance(node, parsetree.ControlLine)
-                and control_frame.is_ternary(node.keyword)
+            if (
+                not (
+                    isinstance(node, parsetree.ControlLine)
+                    and control_frame.is_ternary(node.keyword)
+                )
+                and self.ternary_stack
+                and self.ternary_stack[-1]
             ):
-                if self.ternary_stack and self.ternary_stack[-1]:
-                    self.ternary_stack[-1][-1].nodes.append(node)
+                self.ternary_stack[-1][-1].nodes.append(node)
         if isinstance(node, parsetree.Tag):
             if len(self.tag):
                 node.parent = self.tag[-1]
@@ -207,11 +200,7 @@ class Lexer:
                 )
         else:
             m = self._coding_re.match(text.decode("utf-8", "ignore"))
-            if m:
-                parsed_encoding = m.group(1)
-            else:
-                parsed_encoding = known_encoding or "utf-8"
-
+            parsed_encoding = m.group(1) if m else known_encoding or "utf-8"
         if decode_raw:
             try:
                 text = text.decode(parsed_encoding)
@@ -301,35 +290,34 @@ class Lexer:
             re.I | re.S | re.X,
         )
 
-        if match:
-            keyword, attr, isend = match.groups()
-            self.keyword = keyword
-            attributes = {}
-            if attr:
-                for att in re.findall(
-                    r"\s*(\w+)\s*=\s*(?:'([^']*)'|\"([^\"]*)\")", attr
-                ):
-                    key, val1, val2 = att
-                    text = val1 or val2
-                    text = text.replace("\r\n", "\n")
-                    attributes[key] = text
-            self.append_node(parsetree.Tag, keyword, attributes)
-            if isend:
-                self.tag.pop()
-            else:
-                if keyword == "text":
-                    match = self.match(r"(.*?)(?=\</%text>)", re.S)
-                    if not match:
-                        raise exceptions.SyntaxException(
-                            "Unclosed tag: <%%%s>" % self.tag[-1].keyword,
-                            **self.exception_kwargs,
-                        )
-                    self.append_node(parsetree.Text, match.group(1))
-                    return self.match_tag_end()
-            return True
-        else:
+        if not match:
             return False
 
+        keyword, attr, isend = match.groups()
+        self.keyword = keyword
+        attributes = {}
+        if attr:
+            for att in re.findall(
+                r"\s*(\w+)\s*=\s*(?:'([^']*)'|\"([^\"]*)\")", attr
+            ):
+                key, val1, val2 = att
+                text = val1 or val2
+                text = text.replace("\r\n", "\n")
+                attributes[key] = text
+        self.append_node(parsetree.Tag, keyword, attributes)
+        if isend:
+            self.tag.pop()
+        elif keyword == "text":
+            match = self.match(r"(.*?)(?=\</%text>)", re.S)
+            if not match:
+                raise exceptions.SyntaxException(
+                    "Unclosed tag: <%%%s>" % self.tag[-1].keyword,
+                    **self.exception_kwargs
+                )
+            self.append_node(parsetree.Text, match.group(1))
+            return self.match_tag_end()
+        return True
+
     def match_tag_end(self):
         match = self.match(r"\</%[\t ]*(.+?)[\t ]*>")
         if match:
@@ -352,15 +340,15 @@ class Lexer:
 
     def match_end(self):
         match = self.match(r"\Z", re.S)
-        if match:
-            string = match.group()
-            if string:
-                return string
-            else:
-                return True
-        else:
+        if not match:
             return False
 
+        string = match.group()
+        if string:
+            return string
+        else:
+            return True
+
     def match_text(self):
         match = self.match(
             r"""
@@ -411,63 +399,63 @@ class Lexer:
 
     def match_expression(self):
         match = self.match(r"\${")
-        if match:
-            line, pos = self.matched_lineno, self.matched_charpos
-            text, end = self.parse_until_text(True, r"\|", r"}")
-            if end == "|":
-                escapes, end = self.parse_until_text(True, r"}")
-            else:
-                escapes = ""
-            text = text.replace("\r\n", "\n")
-            self.append_node(
-                parsetree.Expression,
-                text,
-                escapes.strip(),
-                lineno=line,
-                pos=pos,
-            )
-            return True
-        else:
+        if not match:
             return False
 
+        line, pos = self.matched_lineno, self.matched_charpos
+        text, end = self.parse_until_text(True, r"\|", r"}")
+        if end == "|":
+            escapes, end = self.parse_until_text(True, r"}")
+        else:
+            escapes = ""
+        text = text.replace("\r\n", "\n")
+        self.append_node(
+            parsetree.Expression,
+            text,
+            escapes.strip(),
+            lineno=line,
+            pos=pos,
+        )
+        return True
+
     def match_control_line(self):
         match = self.match(
             r"(?<=^)[\t ]*(%(?!%)|##)[\t ]*((?:(?:\\r?\n)|[^\r\n])*)"
             r"(?:\r?\n|\Z)",
             re.M,
         )
-        if match:
-            operator = match.group(1)
-            text = match.group(2)
-            if operator == "%":
-                m2 = re.match(r"(end)?(\w+)\s*(.*)", text)
-                if not m2:
+        if not match:
+            return False
+
+        operator = match.group(1)
+        text = match.group(2)
+        if operator == "%":
+            m2 = re.match(r"(end)?(\w+)\s*(.*)", text)
+            if not m2:
+                raise exceptions.SyntaxException(
+                    "Invalid control line: '%s'" % text,
+                    **self.exception_kwargs
+                )
+            isend, keyword = m2.group(1, 2)
+            isend = isend is not None
+
+            if isend:
+                if not len(self.control_line):
                     raise exceptions.SyntaxException(
-                        "Invalid control line: '%s'" % text,
-                        **self.exception_kwargs,
+                        "No starting keyword '%s' for '%s'"
+                        % (keyword, text),
+                        **self.exception_kwargs
                     )
-                isend, keyword = m2.group(1, 2)
-                isend = isend is not None
-
-                if isend:
-                    if not len(self.control_line):
-                        raise exceptions.SyntaxException(
-                            "No starting keyword '%s' for '%s'"
-                            % (keyword, text),
-                            **self.exception_kwargs,
-                        )
-                    elif self.control_line[-1].keyword != keyword:
-                        raise exceptions.SyntaxException(
-                            "Keyword '%s' doesn't match keyword '%s'"
-                            % (text, self.control_line[-1].keyword),
-                            **self.exception_kwargs,
-                        )
-                self.append_node(parsetree.ControlLine, keyword, isend, text)
-            else:
-                self.append_node(parsetree.Comment, text)
-            return True
+                elif self.control_line[-1].keyword != keyword:
+                    raise exceptions.SyntaxException(
+                        "Keyword '%s' doesn't match keyword '%s'"
+                        % (text, self.control_line[-1].keyword),
+                        **self.exception_kwargs
+                    )
+            self.append_node(parsetree.ControlLine, keyword, isend, text)
         else:
-            return False
+            self.append_node(parsetree.Comment, text)
+        return True
 
     def match_comment(self):
         """matches the multiline version of a comment"""