factor out utility functions

Author: Kareem Zidane

src/cs50/_statement.py

@@ -1,12 +1,18 @@
 """Parses a SQL statement and replaces the placeholders with the corresponding parameters"""
 
 import collections
-import enum
-import re
-
-import sqlparse
 
 from ._sql_sanitizer import SQLSanitizer, escape_verbatim_colon
+from ._statement_util import (
+    _format_and_parse,
+    _get_human_readable_list,
+    _is_identifier,
+    _is_operation_token,
+    _is_placeholder,
+    _is_string_literal,
+    _Paramstyle,
+    _parse_placeholder,
+)
 
 
 class Statement:
@@ -146,69 +152,3 @@ def get_operation_keyword(self):
 
     def __str__(self):
         return "".join([str(token) for token in self._tokens])
-
-
-def _format_and_parse(sql):
-    formatted_statements = sqlparse.format(sql, strip_comments=True).strip()
-    parsed_statements = sqlparse.parse(formatted_statements)
-    statement_count = len(parsed_statements)
-    if statement_count == 0:
-        raise RuntimeError("missing statement")
-    if statement_count > 1:
-        raise RuntimeError("too many statements at once")
-
-    return parsed_statements[0]
-
-
-def _is_placeholder(ttype):
-    return ttype == sqlparse.tokens.Name.Placeholder
-
-
-def _parse_placeholder(value):
-    if value == "?":
-        return _Paramstyle.QMARK, None
-
-    # E.g., :1
-    matches = re.search(r"^:([1-9]\d*)$", value)
-    if matches:
-        return _Paramstyle.NUMERIC, int(matches.group(1)) - 1
-
-    # E.g., :foo
-    matches = re.search(r"^:([a-zA-Z]\w*)$", value)
-    if matches:
-        return _Paramstyle.NAMED, matches.group(1)
-
-    if value == "%s":
-        return _Paramstyle.FORMAT, None
-
-    # E.g., %(foo)s
-    matches = re.search(r"%\((\w+)\)s$", value)
-    if matches:
-        return _Paramstyle.PYFORMAT, matches.group(1)
-
-    raise RuntimeError(f"{value}: invalid placeholder")
-
-
-def _is_operation_token(ttype):
-    return ttype in {
-        sqlparse.tokens.Keyword, sqlparse.tokens.Keyword.DDL, sqlparse.tokens.Keyword.DML}
-
-
-def _is_string_literal(ttype):
-    return ttype in [sqlparse.tokens.Literal.String, sqlparse.tokens.Literal.String.Single]
-
-
-def _is_identifier(ttype):
-    return ttype == sqlparse.tokens.Literal.String.Symbol
-
-
-def _get_human_readable_list(iterable):
-    return ", ".join(str(v) for v in iterable)
-
-
-class _Paramstyle(enum.Enum):
-    FORMAT = enum.auto()
-    NAMED = enum.auto()
-    NUMERIC = enum.auto()
-    PYFORMAT = enum.auto()
-    QMARK = enum.auto()

src/cs50/_statement_util.py

@@ -0,0 +1,72 @@
+"""Utility functions used by _statement.py"""
+
+import enum
+import re
+
+import sqlparse
+
+
+class _Paramstyle(enum.Enum):
+    FORMAT = enum.auto()
+    NAMED = enum.auto()
+    NUMERIC = enum.auto()
+    PYFORMAT = enum.auto()
+    QMARK = enum.auto()
+
+
+def _format_and_parse(sql):
+    formatted_statements = sqlparse.format(sql, strip_comments=True).strip()
+    parsed_statements = sqlparse.parse(formatted_statements)
+    statement_count = len(parsed_statements)
+    if statement_count == 0:
+        raise RuntimeError("missing statement")
+    if statement_count > 1:
+        raise RuntimeError("too many statements at once")
+
+    return parsed_statements[0]
+
+
+def _is_placeholder(ttype):
+    return ttype == sqlparse.tokens.Name.Placeholder
+
+
+def _parse_placeholder(value):
+    if value == "?":
+        return _Paramstyle.QMARK, None
+
+    # E.g., :1
+    matches = re.search(r"^:([1-9]\d*)$", value)
+    if matches:
+        return _Paramstyle.NUMERIC, int(matches.group(1)) - 1
+
+    # E.g., :foo
+    matches = re.search(r"^:([a-zA-Z]\w*)$", value)
+    if matches:
+        return _Paramstyle.NAMED, matches.group(1)
+
+    if value == "%s":
+        return _Paramstyle.FORMAT, None
+
+    # E.g., %(foo)s
+    matches = re.search(r"%\((\w+)\)s$", value)
+    if matches:
+        return _Paramstyle.PYFORMAT, matches.group(1)
+
+    raise RuntimeError(f"{value}: invalid placeholder")
+
+
+def _is_operation_token(ttype):
+    return ttype in {
+        sqlparse.tokens.Keyword, sqlparse.tokens.Keyword.DDL, sqlparse.tokens.Keyword.DML}
+
+
+def _is_string_literal(ttype):
+    return ttype in [sqlparse.tokens.Literal.String, sqlparse.tokens.Literal.String.Single]
+
+
+def _is_identifier(ttype):
+    return ttype == sqlparse.tokens.Literal.String.Symbol
+
+
+def _get_human_readable_list(iterable):
+    return ", ".join(str(v) for v in iterable)