Add whitespace checks for match and case

1 files changed, 27 insertions, 0 deletions

diff --git a/pycodestyle.py b/pycodestyle.py
index 0f2f078..abadf6e 100755
--- a/pycodestyle.py
+++ b/pycodestyle.py
@@ -163,6 +163,7 @@ STARTSWITH_INDENT_STATEMENT_REGEX = re.compile(
     )))
 )
 DUNDER_REGEX = re.compile(r'^__([^\s]+)__ = ')
+MATCH_CASE_REGEX = re.compile(r'^\s*\b(?:match|case)(\s*)(?=.*\:)')
 
 _checks = {'physical_line': {}, 'logical_line': {}, 'tree': {}}
 
@@ -513,6 +514,32 @@ def missing_whitespace_after_import_keyword(logical_line):
 
 
 @register_check
+def missing_whitespace_after_match_case(logical_line):
+    r"""Check whitespace after 'match' and 'case'.
+
+    Python 3.10
+    Okay: match status:
+    E271: match  status:
+    E271: case\tstatus:
+    E271: case   _:
+    E275: matchstatus:
+    E275: casestatus:
+    E275: case_:
+    """
+    if sys.version_info < (3, 10):
+        return
+    match = MATCH_CASE_REGEX.match(logical_line)
+    if match:
+        whitespace = match.groups()[0]
+        if whitespace == ' ':
+            return
+        if whitespace == '':
+            yield match.start(1), "E275 missing whitespace after keyword"
+        else:
+            yield match.start(1), "E271 multiple spaces after keyword"
+
+
+@register_check
 def missing_whitespace(logical_line):
     r"""Each comma, semicolon or colon should be followed by whitespace.