Add methods for working with csv data

gn3/csvcmp.py: New file
(create_dirs_if_not_exists): From a list of dirs, create them if they don't
exist.
(remove_insignificant_edits): Given a dict with a "Modification" key, remove
edits with "delta < ε".
(csv_diff): Generate a csv_diff using the "csvdiff" tool packaged in guix.

tests/unit/test_csvcmp.py: Add some tests for "gn3/csvcmp.py"

1 files changed, 41 insertions, 0 deletions

diff --git a/tests/unit/test_csvcmp.py b/tests/unit/test_csvcmp.py
new file mode 100644
index 0000000..f73865d
--- /dev/null
+++ b/tests/unit/test_csvcmp.py
@@ -0,0 +1,41 @@
+from gn3.csvcmp import csv_diff
+from gn3.csvcmp import remove_insignificant_edits
+
+import pytest
+
+
+@pytest.mark.unit_test
+def test_remove_insignificant_data():
+    diff_data = {
+        'Additions': [],
+        'Deletions': [],
+        'Modifications': [
+            {'Current': '1.000001,3', 'Original': '1,3'},
+            {'Current': '1,3', 'Original': '1.000001,3'},
+            {'Current': '2.000001,3', 'Original': '2,2'},
+            {'Current': '1.01,3', 'Original': '1,2'}
+        ]
+    }
+    expected_json = {
+        'Additions': [],
+        'Deletions': [],
+        'Modifications': [
+            {'Current': '2,3', 'Original': '2,2'},
+            {'Current': '1.01,3', 'Original': '1,2'}
+        ]
+    }
+    assert (remove_insignificant_edits(diff_data) ==
+            expected_json)
+
+
+@pytest.mark.unit_test
+def test_csv_diff():
+    test_results = csv_diff(base_csv="a,b\n1,2\n",
+                            delta_csv="a,b\n1,3")
+    _json = {
+        'Additions': [],
+        'Deletions': [],
+        'Modifications': [{'Current': '1,3', 'Original': '1,2'}]
+    }
+    assert(test_results.get("code") == 0 and
+           test_results.get("output") == _json)