python implementation of ls to mimick ls behavior

Author: SaraTahir28

implement-shell-tools/ls/ls.py

@@ -0,0 +1,54 @@
+import argparse
+import os    #interacting with the filesystem (paths, directories)
+import sys   #access to system streams (stdout, stderr) and arguments
+
+def parseargs():
+    parser = argparse.ArgumentParser(
+        prog = "ls",
+        description = "ls clone to -1 and -a flags"
+    )
+    parser.add_argument("-1", dest = "one_per_line", action = "store_true",help = "List one file per line") #dest sets the attribute name in parsed argument.
+    parser.add_argument("-a", "--all", action ="store_true",help = "Include directory entries whose names begin with a dot (.)")
+    parser.add_argument("dirs", nargs = "*", default = ["."], help = "Directories to list (default is current directory)")
+    return parser.parse_args()
+
+def print_directory_entries(path, one_per_line=False, show_all=False):
+    try:
+        # Retrieve all entries (files and subdirectories) inside the given path
+        directory_entries = os.listdir(path)
+    except FileNotFoundError:
+        # If the directory doesn't exist, print an error to stderr
+        print(f"ls: cannot access '{path}': No such file or directory", file=sys.stderr)
+        return
+    except PermissionError:
+        # If the directory exists but we don't have permission, print an error
+        print(f"ls: cannot open directory '{path}': Permission denied", file=sys.stderr)
+        return
+
+    # By default, ls hides "dotfiles" (names starting with ".").
+    # Only include them if the -a flag (show_all=True) is set.
+    if not show_all:
+        directory_entries = [entry for entry in directory_entries if not entry.startswith(".")]
+
+    # Sort entries alphabetically for consistent output
+    directory_entries.sort()
+
+    if one_per_line:
+        # If -1 flag is set, print each entry on its own line
+        for entry_name in directory_entries:
+            print(entry_name)
+    else:
+        # Default behavior: print entries space-separated on one line
+        print("  ".join(directory_entries))
+
+def main():
+    args = parseargs()
+    # Loop through each directory provided
+    for directory in args.dirs:
+        print_directory_entries(
+            directory,
+            one_per_line = args.one_per_line,
+            show_all = args.all
+        )
+if __name__ == "__main__":
+    main()