Initial commit

skills/argparse-patterns/templates/variadic-args.py

@@ -0,0 +1,164 @@
+#!/usr/bin/env python3
+"""
+Variadic argument patterns (nargs: ?, *, +, number).
+
+Usage:
+    python variadic-args.py file1.txt file2.txt file3.txt
+    python variadic-args.py --output result.json file1.txt file2.txt
+    python variadic-args.py --include *.py --exclude test_*.py
+"""
+
+import argparse
+import sys
+from pathlib import Path
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description='Variadic argument patterns',
+        formatter_class=argparse.RawDescriptionHelpFormatter
+    )
+
+    # ===== nargs='?' (optional, 0 or 1) =====
+    parser.add_argument(
+        '--output',
+        nargs='?',
+        const='default.json',  # Used if flag present but no value
+        default=None,  # Used if flag not present
+        help='Output file (default: stdout, or default.json if flag present)'
+    )
+
+    parser.add_argument(
+        '--config',
+        nargs='?',
+        const='config.yaml',
+        help='Configuration file (default: config.yaml if flag present)'
+    )
+
+    # ===== nargs='*' (zero or more) =====
+    parser.add_argument(
+        '--include',
+        nargs='*',
+        default=[],
+        help='Include patterns (zero or more)'
+    )
+
+    parser.add_argument(
+        '--exclude',
+        nargs='*',
+        default=[],
+        help='Exclude patterns (zero or more)'
+    )
+
+    parser.add_argument(
+        '--tags',
+        nargs='*',
+        metavar='TAG',
+        help='Tags to apply'
+    )
+
+    # ===== nargs='+' (one or more, required) =====
+    parser.add_argument(
+        'files',
+        nargs='+',
+        type=Path,
+        help='Input files (at least one required)'
+    )
+
+    parser.add_argument(
+        '--servers',
+        nargs='+',
+        metavar='SERVER',
+        help='Server addresses (at least one required if specified)'
+    )
+
+    # ===== nargs=N (exact number) =====
+    parser.add_argument(
+        '--coordinates',
+        nargs=2,
+        type=float,
+        metavar=('LAT', 'LON'),
+        help='Coordinates as latitude longitude'
+    )
+
+    parser.add_argument(
+        '--range',
+        nargs=2,
+        type=int,
+        metavar=('START', 'END'),
+        help='Range as start end'
+    )
+
+    parser.add_argument(
+        '--rgb',
+        nargs=3,
+        type=int,
+        metavar=('R', 'G', 'B'),
+        help='RGB color values (0-255)'
+    )
+
+    # ===== Remainder arguments =====
+    parser.add_argument(
+        '--command',
+        nargs=argparse.REMAINDER,
+        help='Command and arguments to pass through'
+    )
+
+    # Parse arguments
+    args = parser.parse_args()
+
+    # Display results
+    print("Variadic Arguments Results:")
+
+    print("\nnargs='?' (optional):")
+    print(f"  Output: {args.output}")
+    print(f"  Config: {args.config}")
+
+    print("\nnargs='*' (zero or more):")
+    print(f"  Include Patterns: {args.include if args.include else '(none)'}")
+    print(f"  Exclude Patterns: {args.exclude if args.exclude else '(none)'}")
+    print(f"  Tags: {args.tags if args.tags else '(none)'}")
+
+    print("\nnargs='+' (one or more):")
+    print(f"  Files ({len(args.files)}):")
+    for f in args.files:
+        print(f"    - {f}")
+    if args.servers:
+        print(f"  Servers ({len(args.servers)}):")
+        for s in args.servers:
+            print(f"    - {s}")
+
+    print("\nnargs=N (exact number):")
+    if args.coordinates:
+        lat, lon = args.coordinates
+        print(f"  Coordinates: {lat}, {lon}")
+    if args.range:
+        start, end = args.range
+        print(f"  Range: {start} to {end}")
+    if args.rgb:
+        r, g, b = args.rgb
+        print(f"  RGB Color: rgb({r}, {g}, {b})")
+
+    print("\nRemaining arguments:")
+    if args.command:
+        print(f"  Command: {' '.join(args.command)}")
+
+    # Example usage
+    print("\nExample Processing:")
+    print(f"Processing {len(args.files)} file(s)...")
+
+    if args.include:
+        print(f"Including patterns: {', '.join(args.include)}")
+    if args.exclude:
+        print(f"Excluding patterns: {', '.join(args.exclude)}")
+
+    if args.output:
+        print(f"Output will be written to: {args.output}")
+    else:
+        print("Output will be written to: stdout")
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())