Refactor cat implementationinto functions for readability

Author: ike-agu

implement-shell-tools/cat/cat.py

@@ -1,46 +1,63 @@
 import argparse
-# -------------------------------------------
-# Set up the argument parser
-# -------------------------------------------
 
-parser = argparse.ArgumentParser(
-    prog ="display-file-content",
-    description = "Implement cat command with -n and -b flag support",
-    )
+def parse_args():
+    parser = argparse.ArgumentParser(
+        prog ="display-file-content",
+        description = "Implement cat command with -n and -b flag support",
+        )
 
-parser.add_argument("-n", "--number-all-lines",
-                    action="store_true",
-                    help="Number every line in the file"
-                    )
+    parser.add_argument("-n", "--number-all-lines",
+                        action="store_true",
+                        help="Number every line in the file"
+                        )
 
-parser.add_argument("-b", "--number-non-empty-lines",
-                    action="store_true",
-                    help="Number non empty lines in the file"
-                    )
+    parser.add_argument("-b", "--number-non-empty-lines",
+                        action="store_true",
+                        help="Number non empty lines in the file"
+                        )
 
-parser.add_argument("paths", nargs="+", help="File paths to process")
+    parser.add_argument("paths", nargs="+", help="File paths to process")
 
-args = parser.parse_args()
+    args = parser.parse_args()
+    return args
 
-# -------------------------------------------
-#  Implement functionality
-# -------------------------------------------
 
-line_number = 1
+def print_line(line, line_number = None):
+    if line_number is None:
+        print(line, end="")
+    else:
+        print(f"{line_number} {line}", end="")
 
-for filepath in args.paths:
+def process_line(line, args, line_number):
+    if args.number_non_empty_lines:
+        if line.strip() == "":
+            print_line(line)
+        else:
+            print_line(line, line_number)
+            line_number += 1
+
+    elif args.number_all_lines:
+        print_line(line, line_number)
+        line_number +=1
+
+    else:
+        print_line(line)
+
+    return line_number
+
+def process_file(filepath, args, line_number):
+    """Read a file and print its lines. Returns updated line_number."""
     with open(filepath, "r", encoding="utf-8") as f:
         for line in f:
-            if args.number_non_empty_lines:
-                if line.strip() == "":
-                    print(line, end="")
-                else:
-                    print(f"{line_number} {line}", end="")
-                    line_number += 1
-
-            elif args.number_all_lines:
-                    print(f"{line_number} {line}", end="")
-                    line_number +=1
-
-            else:
-                print(line, end="")
+            line_number = process_line(line, args, line_number)
+    return line_number
+
+def main():
+    args = parse_args()
+    line_number = 1
+
+    for filepath in args.paths:
+        line_number = process_file(filepath, args, line_number)
+
+if __name__ == "__main__":
+    main()