Feat: Add patterns to ignore files in the reference directory

README.md

@@ -174,7 +174,7 @@ specific_args = {
 }
 ```
 
-And last but not least, it's possible to use regular expressions to associate specific arguments to
+Another possibility is to use regular expressions to associate specific arguments to
 a set of files:
 
 ```python
@@ -186,6 +186,16 @@ specific_args = {
 }
 ```
 
+And last but not least, it's possible to ignore a set of files from the reference directory (for
+example because the reference directory contains temporary files that should not be compared). For
+example, the following code will ignore all files whose name ends with `_tmp.yaml`:
+
+```python
+import dir_content_diff
+
+dir_content_diff.compare_trees("reference_dir", "compared_dir", ignore_patterns=[r".*_tmp\.yaml"])
+```
+
 
 ### Export formatted data
 

dir_content_diff/__init__.py

@@ -259,6 +259,7 @@ def compare_trees(
     specific_args=None,
     return_raw_diffs=False,
     export_formatted_files=False,
+    ignore_patterns=None,
 ):
     """Compare all files from 2 different directory trees and return the differences.
 
@@ -306,6 +307,9 @@ def compare_trees(
             new directory with formatted compared data files. If a string is passed, this string is
             used as suffix for the new directory. If `True` is passed, the suffix is
             ``_FORMATTED``.
+        ignore_patterns (list): A list of regular expression patterns. If the relative path of a
+            file matches one of these patterns, it is ignored during the comparison. Note that
+            this means that any specific arguments for that file will also be ignored.
 
     Returns:
         dict: A ``dict`` in which the keys are the relative file paths and the values are the
@@ -333,6 +337,11 @@ def compare_trees(
         for pattern in v.pop("patterns", []):
             pattern_specific_args[re.compile(pattern)] = v
 
+    if ignore_patterns is None:
+        ignore_patterns = []
+    else:
+        ignore_patterns = [re.compile(i) for i in ignore_patterns]
+
     # Loop over all files and call the correct comparator
     different_files = {}
     for ref_file in ref_path.glob("**/*"):
@@ -342,6 +351,14 @@ def compare_trees(
         relative_path = ref_file.relative_to(ref_path).as_posix()
         comp_file = comp_path / relative_path
 
+        ignored = False
+        for pattern in ignore_patterns:
+            if pattern.match(relative_path):
+                ignored = True
+                break
+        if ignored:
+            continue
+
         if comp_file.exists():
             specific_file_args = specific_args.get(relative_path, None)
             if specific_file_args is None:

tests/test_base.py

@@ -1018,6 +1018,26 @@ def test_diff_tree(
         ]:
             assert match_i is not None
 
+    def test_diff_tree_ignore(
+        self, ref_tree, res_tree_diff, pdf_diff, dict_diff, xml_diff, ini_diff
+    ):
+        """Test that the returned differences are correct even with ignored files."""
+        res = compare_trees(
+            ref_tree, res_tree_diff, ignore_patterns=[r".*\.yaml", r".*\.ini"]
+        )
+
+        assert len(res) == 3
+        match_res_0 = re.match(pdf_diff, res["file.pdf"])
+        match_res_1 = re.match(dict_diff, res["file.json"])
+        match_res_3 = re.match(xml_diff, res["file.xml"])
+
+        for match_i in [
+            match_res_0,
+            match_res_1,
+            match_res_3,
+        ]:
+            assert match_i is not None
+
     def test_assert_equal_trees(
         self, ref_tree, res_tree_diff, pdf_diff, dict_diff, xml_diff
     ):