python implementation of wc

Author: SaraTahir28

implement-shell-tools/wc/wc.py

@@ -0,0 +1,82 @@
+import argparse
+import sys
+import glob # to find file paths and match patterns
+
+def parseargs():
+    parser = argparse.ArgumentParser(
+        prog = "wc",
+        description = "wc clone supporting -l, -w, -c flags"
+    )
+    parser.add_argument("-l", "--lines", action = "store_true",help = "print line counts")
+    parser.add_argument("-w", "--words", action ="store_true",help = "print word count")
+    parser.add_argument("-c", "--bytes", action ="store_true", help = "print byte count")
+    parser.add_argument("files", nargs="+", help="Files to read (shell globs allowed)")
+
+    return parser.parse_args()
+
+   #Uses glob to expand patterns like *.txt.
+def expand_files(patterns):
+    expanded = []
+    for p in patterns:
+        matches = glob.glob(p)
+        if matches:
+            expanded.extend(sorted(matches))  # predictable order
+        else:
+            print(f"wc: {p}: No such file", file=sys.stderr) #Prints an error if a pattern matches nothing.
+    return expanded
+
+def file_counts(filename):
+    try:
+        with open(filename, "rb") as f: #opening file in binary mode to be able to count bytes.
+            data = f.read()
+    except FileNotFoundError:
+        print(f"wc: {filename}: No such file", file=sys.stderr)
+        return None
+
+    text = data.decode("utf-8", errors="ignore")
+    line_count = text.count("\n")
+    word_count = len(text.split())
+    byte_count = len(data)
+
+    return line_count, word_count, byte_count
+
+def print_counts(filename, counts, show_lines, show_words, show_bytes): #args.lines is passed into the parameter show_lines and same for other arguments.
+    line_count, word_count, byte_count = counts
+
+    # If no flags are set, show all three
+    if not (show_lines or show_words or show_bytes):
+        print(f"{line_count:7} {word_count:7} {byte_count:7} {filename}")
+        return
+
+    output = []
+    if show_lines:
+        output.append(f"{line_count:7}") #:7 to ensure nums are rightaligned in a spaced column -just like GNU wc
+    if show_words:
+        output.append(f"{word_count:7}")
+    if show_bytes:
+        output.append(f"{byte_count:7}")
+    output.append(filename)
+    print(" ".join(output))
+
+def main():
+    args = parseargs()
+    files = expand_files(args.files)
+
+    total_lines, total_words, total_bytes = 0, 0, 0
+
+    for file in files:
+        counts = file_counts(file)
+        if counts is None:
+            continue
+        print_counts(file, counts, args.lines, args.words, args.bytes)
+        total_lines += counts[0]
+        total_words += counts[1]
+        total_bytes += counts[2]
+
+    # If multiple files, print totals
+    if len(files) > 1:
+        total_counts = (total_lines, total_words, total_bytes)
+        print_counts("total", total_counts, args.lines, args.words, args.bytes)
+
+if __name__ == "__main__":
+    main()