Further improvements to human_text

Author: simonw

README.md

@@ -22,20 +22,24 @@ Consider two CSV files:
 `csv-diff` can show a human-readable summary of differences between the files:
 
     $ csv-diff one.csv two.csv --key=id
-    1 row added, 1 row removed, 1 row changed
+    1 row changed, 1 row added, 1 row removed
 
-    1 row added
+    1 row changed
 
-      {"id": "3", "name": "Bailey", "age": "1"}
+      Row 1
+        age: "4" => "5"
 
-    1 row removed
+    1 row added
 
-      {"id": "2", "name": "Pancakes", "age": "2"}
+      id: 3
+      name: Bailey
+      age: 1
 
-    1 row changed
+    1 row removed
 
-      Row 1
-        age: "4" => "5"
+      id: 2
+      name: Pancakes
+      age: 2
 
 The `--key=id` option means that the `id` column should be treated as the unique key, to identify which records have changed.
 

csv_diff/__init__.py

@@ -43,7 +43,7 @@ def compare(previous, current):
     return result
 
 
-def human_text(result):
+def human_text(result, key=None):
     title = []
     summary = []
     show_headers = sum(1 for key in result if result[key]) > 1
@@ -57,7 +57,7 @@ def human_text(result):
         change_blocks = []
         for details in result["changed"]:
             block = []
-            block.append("  Row {}".format(details["key"]))
+            block.append("  {}: {}".format(key, details["key"]))
             for field, (prev_value, current_value) in details["changes"].items():
                 block.append(
                     '    {}: "{}" => "{}"'.format(field, prev_value, current_value)
@@ -72,9 +72,10 @@ def human_text(result):
         title.append(fragment)
         if show_headers:
             summary.append(fragment + "\n")
+        rows = []
         for row in result["added"]:
-            summary.append(human_row(row, prefix="  "))
-            summary.append("")
+            rows.append(human_row(row, prefix="  "))
+        summary.append("\n\n".join(rows))
         summary.append("")
     if result["removed"]:
         fragment = "{} row{} removed".format(
@@ -83,9 +84,10 @@ def human_text(result):
         title.append(fragment)
         if show_headers:
             summary.append(fragment + "\n")
+        rows = []
         for row in result["removed"]:
-            summary.append(human_row(row, prefix="  "))
-            summary.append("")
+            rows.append(human_row(row, prefix="  "))
+        summary.append("\n\n".join(rows))
         summary.append("")
     return (", ".join(title) + "\n\n" + ("\n".join(summary))).strip()
 

csv_diff/cli.py

@@ -25,4 +25,4 @@ def cli(previous, current, key, json):
     if json:
         print(std_json.dumps(diff, indent=4))
     else:
-        print(human_text(diff))
+        print(human_text(diff, key))

tests/test_cli.py

@@ -2,6 +2,7 @@
 from csv_diff import cli
 from .test_csv_diff import ONE, TWO, THREE
 import json
+from textwrap import dedent
 
 
 def test_human_cli(tmpdir):
@@ -11,7 +12,12 @@ def test_human_cli(tmpdir):
     two.write(TWO)
     result = CliRunner().invoke(cli.cli, [str(one), str(two), "--key", "id"])
     assert 0 == result.exit_code
-    assert '1 row changed\n\n  Row 1\n    age: "4" => "5"' == result.output.strip()
+    assert dedent("""
+    1 row changed
+
+      id: 1
+        age: "4" => "5"
+    """).strip() == result.output.strip()
 
 
 def test_human_cli_json(tmpdir):

tests/test_human_text.py

@@ -7,6 +7,10 @@
 3,Bailey,1
 4,Carl,7"""
 
+SIX = """id,name,age
+1,Cleo,5
+3,Bailey,1"""
+
 from textwrap import dedent
 import io
 
@@ -18,9 +22,9 @@ def test_row_changed():
     assert dedent("""
     1 row changed
 
-      Row 1
+      id: 1
         age: "4" => "5"
-    """).strip() == human_text(diff)
+    """).strip() == human_text(diff, "id")
 
 
 def test_row_added():
@@ -33,7 +37,7 @@ def test_row_added():
       id: 2
       name: Pancakes
       age: 2
-    """).strip() == human_text(diff)
+    """).strip() == human_text(diff, "id")
 
 
 def test_rows_added():
@@ -54,7 +58,7 @@ def test_rows_added():
       id: 4
       name: Carl
       age: 7
-    """).strip() == human_text(diff)
+    """).strip() == human_text(diff, "id")
 
 
 def test_row_removed():
@@ -67,25 +71,31 @@ def test_row_removed():
       id: 2
       name: Pancakes
       age: 2
-    """).strip() == human_text(diff)
+    """).strip() == human_text(diff, "id")
 
 
-def test_row_changed_and_row_added():
+def test_row_changed_and_row_added_and_row_deleted():
     "Should have headers for each section here"
     diff = compare(
-        load_csv(io.StringIO(ONE), key="id"), load_csv(io.StringIO(FOUR), key="id")
+        load_csv(io.StringIO(ONE), key="id"), load_csv(io.StringIO(SIX), key="id")
     )
     assert dedent("""
-    1 row changed, 1 row added
+    1 row changed, 1 row added, 1 row removed
 
     1 row changed
 
-      Row 1
+      id: 1
         age: "4" => "5"
 
     1 row added
 
       id: 3
       name: Bailey
       age: 1
-    """).strip() == human_text(diff)
+
+    1 row removed
+
+      id: 2
+      name: Pancakes
+      age: 2
+    """).strip() == human_text(diff, "id")