implement wc command in python

Author: Pezhman-Azizi

implement-shell-tools/wc/wc.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+import sys
+import glob
+import os
+
+def count_file(filename, count_lines, count_words, count_bytes):
+    try:
+        with open(filename, "rb") as f:  # open in binary to count bytes correctly
+            data = f.read()
+    except FileNotFoundError:
+        print(f"wc: {filename}: No such file or directory", file=sys.stderr)
+        return None
+
+    text = data.decode(errors="ignore")
+    lines = text.splitlines()
+
+    l = len(lines)
+    w = len(text.split())
+    c = len(data)
+
+    results = []
+    if count_lines:
+        results.append(str(l))
+    if count_words:
+        results.append(str(w))
+    if count_bytes:
+        results.append(str(c))
+
+    if not (count_lines or count_words or count_bytes):
+        # default: all three
+        results = [str(l), str(w), str(c)]
+
+    return results, filename, (l, w, c)
+
+def main():
+    args = sys.argv[1:]
+
+    count_lines = "-l" in args
+    count_words = "-w" in args
+    count_bytes = "-c" in args
+
+    # remove flags from args
+    files = [arg for arg in args if arg not in ("-l", "-w", "-c")]
+
+    if not files:
+        print("wc: missing file operand", file=sys.stderr)
+        sys.exit(1)
+
+    expanded_files = []
+    for f in files:
+        expanded_files.extend(glob.glob(f))
+
+    if not expanded_files:
+        print("wc: no matching files", file=sys.stderr)
+        sys.exit(1)
+
+    total_l, total_w, total_c = 0, 0, 0
+
+    for filename in expanded_files:
+        result = count_file(filename, count_lines, count_words, count_bytes)
+        if result:
+            res, name, (l, w, c) = result
+            print(f"{' '.join(res)} {name}")
+            total_l += l
+            total_w += w
+            total_c += c
+
+    if len(expanded_files) > 1:
+        total_results = []
+        if count_lines:
+            total_results.append(str(total_l))
+        if count_words:
+            total_results.append(str(total_w))
+        if count_bytes:
+            total_results.append(str(total_c))
+        if not (count_lines or count_words or count_bytes):
+            total_results = [str(total_l), str(total_w), str(total_c)]
+        print(f"{' '.join(total_results)} total")
+
+if __name__ == "__main__":
+    main()