Merge pull request #92 from dbcli/RW/add-headerless-csv-formats

Add headerless variants of CSV and TSV formats

Author: rolandwalker

CHANGELOG

@@ -1,5 +1,7 @@
 # Changelog
 
+- Added noheader CSV and TSV output formats.
+
 ## Version 2.4.0
 
 (released on 2025-03-10)

cli_helpers/tabular_output/delimited_output_adapter.py

@@ -8,7 +8,7 @@
 from cli_helpers.utils import filter_dict_by_key
 from .preprocessors import bytes_to_string, override_missing_value
 
-supported_formats = ("csv", "csv-tab")
+supported_formats = ("csv", "csv-tab", "csv-noheader", "csv-tab-noheader")
 preprocessors = (override_missing_value, bytes_to_string)
 
 
@@ -35,9 +35,9 @@ def adapter(data, headers, table_format="csv", **kwargs):
         "skipinitialspace",
         "strict",
     )
-    if table_format == "csv":
+    if table_format in ("csv", "csv-noheader"):
         delimiter = ","
-    elif table_format == "csv-tab":
+    elif table_format in ("csv-tab", "csv-tab-noheader"):
         delimiter = "\t"
     else:
         raise ValueError("Invalid table_format specified.")
@@ -47,8 +47,9 @@ def adapter(data, headers, table_format="csv", **kwargs):
 
     l = linewriter()
     writer = csv.writer(l, **ckwargs)
-    writer.writerow(headers)
-    yield l.line
+    if "noheader" not in table_format:
+        writer.writerow(headers)
+        yield l.line
 
     for row in data:
         l.reset()

cli_helpers/tabular_output/tsv_output_adapter.py

@@ -7,11 +7,17 @@
 from itertools import chain
 from cli_helpers.utils import replace
 
-supported_formats = ("tsv",)
+supported_formats = ("tsv", "tsv_noheader")
 preprocessors = (override_missing_value, bytes_to_string, convert_to_string)
 
 
-def adapter(data, headers, **kwargs):
+def adapter(data, headers, table_format="tsv", **kwargs):
     """Wrap the formatting inside a function for TabularOutputFormatter."""
-    for row in chain((headers,), data):
-        yield "\t".join((replace(r, (("\n", r"\n"), ("\t", r"\t"))) for r in row))
+    if table_format == "tsv":
+        for row in chain((headers,), data):
+            yield "\t".join((replace(r, (("\n", r"\n"), ("\t", r"\t"))) for r in row))
+    elif table_format == "tsv_noheader":
+        for row in data:
+            yield "\t".join((replace(r, (("\n", r"\n"), ("\t", r"\t"))) for r in row))
+    else:
+        raise ValueError(f"Invalid table_format specified: {table_format}.")

tests/tabular_output/test_delimited_output_adapter.py

@@ -42,6 +42,36 @@ def test_csv_wrapper():
         list(output)
 
 
+def test_csv_noheader_wrapper():
+    """Test the delimited output adapter without headers."""
+    # Test comma-delimited output.
+    data = [["abc", "1"], ["d", "456"]]
+    headers = ["letters", "number"]
+    output = delimited_output_adapter.adapter(
+        iter(data),
+        headers,
+        table_format="csv-noheader",
+        dialect="unix",
+    )
+    assert "\n".join(output) == dedent(
+        '''\
+        "abc","1"\n\
+        "d","456"'''
+    )
+
+    # Test tab-delimited output.
+    data = [["abc", "1"], ["d", "456"]]
+    headers = ["letters", "number"]
+    output = delimited_output_adapter.adapter(
+        iter(data), headers, table_format="csv-tab-noheader", dialect="unix"
+    )
+    assert "\n".join(output) == dedent(
+        '''\
+        "abc"\t"1"\n\
+        "d"\t"456"'''
+    )
+
+
 def test_unicode_with_csv():
     """Test that the csv wrapper can handle non-ascii characters."""
     data = [["观音", "1"], ["Ποσειδῶν", "456"]]

tests/tabular_output/test_tsv_output_adapter.py

@@ -23,6 +23,19 @@ def test_tsv_wrapper():
     )
 
 
+def test_tsv_headerless_wrapper():
+    """Test the tsv headerless_output adapter."""
+    # Test tab-delimited output.
+    data = [["ab\r\nc", "1"], ["d", "456"]]
+    headers = ["letters", "number"]
+    output = tsv_output_adapter.adapter(iter(data), headers, table_format="tsv_noheader")
+    assert "\n".join(output) == dedent(
+        """\
+        ab\r\\nc\t1\n\
+        d\t456"""
+    )
+
+
 def test_unicode_with_tsv():
     """Test that the tsv wrapper can handle non-ascii characters."""
     data = [["观音", "1"], ["Ποσειδῶν", "456"]]