FEAT: The PIP command alias feature

news/12828.feature.rst

@@ -0,0 +1 @@
+New command alias functionality based on existing commands.

src/pip/_internal/cli/main_parser.py

@@ -9,7 +9,12 @@
 from pip._internal.build_env import get_runnable_pip
 from pip._internal.cli import cmdoptions
 from pip._internal.cli.parser import ConfigOptionParser, UpdatingDefaultsHelpFormatter
-from pip._internal.commands import commands_dict, get_similar_commands
+from pip._internal.commands import (
+    commands_aliases,
+    commands_dict,
+    find_command_by_alias,
+    get_similar_commands,
+)
 from pip._internal.exceptions import CommandError
 from pip._internal.utils.misc import get_pip_version, get_prog
 
@@ -38,10 +43,21 @@ def create_main_parser() -> ConfigOptionParser:
     parser.main = True  # type: ignore
 
     # create command listing for description
-    description = [""] + [
-        f"{name:27} {command_info.summary}"
-        for name, command_info in commands_dict.items()
-    ]
+    cmds_listings: List[str] = []
+    padding = 27
+    for name, command_info in commands_dict.items():
+        cmd_aliases = commands_aliases.get(name, [])
+        if not cmd_aliases:
+            cmds_listings.append(f"{name:{padding}} {command_info.summary}")
+            continue
+        display_aliases = ", ".join(cmd_aliases)
+        padding_adjusted = padding - len(display_aliases) - 3
+        cmds_listings.append(
+            f"{display_aliases}, {name:{padding_adjusted}}  {command_info.summary}"
+        )
+
+    description = [""] + cmds_listings
+
     parser.description = "\n".join(description)
 
     return parser
@@ -119,13 +135,18 @@ def parse_command(args: List[str]) -> Tuple[str, List[str]]:
     cmd_name = args_else[0]
 
     if cmd_name not in commands_dict:
-        guess = get_similar_commands(cmd_name)
+        alias_command = find_command_by_alias(cmd_name)
+
+        if not alias_command:
+            guess = get_similar_commands(cmd_name)
 
-        msg = [f'unknown command "{cmd_name}"']
-        if guess:
-            msg.append(f'maybe you meant "{guess}"')
+            msg = [f'unknown command "{cmd_name}"']
+            if guess:
+                msg.append(f'maybe you meant "{guess}"')
 
-        raise CommandError(" - ".join(msg))
+            raise CommandError(" - ".join(msg))
+        cmd_name = alias_command
+        args[0] = cmd_name  # replace with the full command name.. ex: i -> install
 
     # all the args without the subcommand
     cmd_args = args[:]

src/pip/_internal/commands/__init__.py

@@ -4,7 +4,8 @@
 
 import importlib
 from collections import namedtuple
-from typing import Any, Dict, Optional
+from itertools import chain
+from typing import Any, Dict, List, Optional
 
 from pip._internal.cli.base_command import Command
 
@@ -105,6 +106,21 @@
     ),
 }
 
+# This dict lists real command aliases from `commands_dict`
+commands_aliases: Dict[str, List[str]] = {
+    "install": ["i", "add"],
+    "uninstall": ["u", "rm", "remove"],
+    "list": ["ls"],
+}
+
+
+def find_command_by_alias(alias: str) -> Optional[str]:
+    """Find command name by alias"""
+    for command, aliases in commands_aliases.items():
+        if alias in aliases:
+            return command
+    return None
+
 
 def create_command(name: str, **kwargs: Any) -> Command:
     """
@@ -125,8 +141,13 @@ def get_similar_commands(name: str) -> Optional[str]:
     name = name.lower()
 
     close_commands = get_close_matches(name, commands_dict.keys())
+    close_aliases = get_close_matches(
+        name, chain.from_iterable(commands_aliases.values())
+    )
 
     if close_commands:
         return close_commands[0]
+    elif close_aliases:
+        return close_aliases[0]
     else:
         return None

src/pip/_internal/commands/help.py

@@ -17,6 +17,7 @@ def run(self, options: Values, args: List[str]) -> int:
         from pip._internal.commands import (
             commands_dict,
             create_command,
+            find_command_by_alias,
             get_similar_commands,
         )
 
@@ -27,13 +28,18 @@ def run(self, options: Values, args: List[str]) -> int:
             return SUCCESS
 
         if cmd_name not in commands_dict:
-            guess = get_similar_commands(cmd_name)
+            alias_command = find_command_by_alias(cmd_name)
 
-            msg = [f'unknown command "{cmd_name}"']
-            if guess:
-                msg.append(f'maybe you meant "{guess}"')
+            if not alias_command:
+                guess = get_similar_commands(cmd_name)
 
-            raise CommandError(" - ".join(msg))
+                msg = [f'unknown command "{cmd_name}"']
+                if guess:
+                    msg.append(f'maybe you meant "{guess}"')
+
+                raise CommandError(" - ".join(msg))
+            cmd_name = alias_command
+            args[0] = cmd_name
 
         command = create_command(cmd_name)
         command.parser.print_help()