updated get_pattern function

Author: Kirushikesh

gptcache/processor/pre.py

@@ -49,28 +49,27 @@ def last_content_without_prompt(data: Dict[str, Any], **params: Dict[str, Any])
 
 
 def _get_pattern_value(pattern_str: str, value_str: str):
-    literal_text_arr = []
-    field_name_arr = []
-    for literal_text, field_name, _, _ in string.Formatter().parse(pattern_str):
-        literal_text_arr.append(literal_text)
-        if field_name is not None:
-            field_name_arr.append(
-                field_name if field_name else str(len(field_name_arr))
-            )
-
-    pattern_values = {}
+    parts = list(string.Formatter().parse(pattern_str))
+    field_names = [field_name for _, field_name, _, _ in parts if field_name is not None]
+    
+    pattern_values = {field: '' for field in field_names}  # Initialize all fields with empty strings
+    
     last_end = 0
-    for i, literal_text in enumerate(literal_text_arr):
-        start = value_str.find(literal_text, last_end)
-        if i == len(literal_text_arr) - 1:
-            end = len(value_str)
-        else:
-            end = value_str.find(literal_text_arr[i + 1], start + 1)
-        if start == -1 or end == -1:
-            break
-        start += len(literal_text)
-        pattern_values[field_name_arr[i]] = value_str[start:end]
-        last_end = end
+    for i, (literal_text, field_name, _, _) in enumerate(parts):
+        if literal_text:
+            start = value_str.find(literal_text, last_end)
+            if start == -1:
+                break
+            if i > 0 and field_names[i-1]:
+                pattern_values[field_names[i-1]] = value_str[last_end:start].strip()
+            last_end = start + len(literal_text)
+        elif i > 0 and field_name:  # Handle consecutive fields
+            pattern_values[field_names[i-1]] = ''
+    
+    # Handle the last field if it exists
+    if field_names and last_end < len(value_str):
+        pattern_values[field_names[-1]] = value_str[last_end:].strip()
+
     return pattern_values