PYTHON(1)

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PYTHON(1) 💅

okay bestie, welcome to the General Commands Manual for python. buckle up, this one's a whole personality 🎀

✨ NAME ✨

python — an interpreted, interactive, object-oriented programming language 🐍💖

yes that's the whole thing. she's a language, she interprets, she interacts, she's object-oriented, she ate.

🌸 SYNOPSIS 🌸

python [ -B ] [ -b ] [ -d ] [ -E ] [ -h ] [ -i ] [ -I ]
       [ -m module-name ] [ -q ] [ -R ] [ -O ] [ -OO ] [ -P ] [ -s ] [ -S ] [ -u ]
       [ -v ] [ -V ] [ -W argument ] [ -x ] [ -X option ] [ -?  ]
       [ --check-hash-based-pycs default | always | never ]
       [ --help ] [ --help-env ] [ --help-xoptions ] [ --help-all ]
       [ -c command | script | - ] [ arguments ]

it's giving "the whole alphabet walked in and sat down" ngl. every single one of those is explained below, no skips, no shortcuts 🫶

🦋 DESCRIPTION 🦋

Python is an interpreted, interactive, object-oriented programming language that combines remarkable power with very clear syntax. iconic combo honestly — like being both gorgeous and smart 💅✨

For an intro to programming in Python, go peek at the Python Tutorial. The Python Library Reference is where you'll find the built-in and standard types, constants, functions and modules all documented. And finally, the Python Reference Manual describes the syntax and semantics of the core language in — and I quote, bestie — (perhaps too) much detail 😭. These documents can be found via the INTERNET RESOURCES below, and they might already be installed on your system too, no biggie.

Python's basic power can be extended with your own modules written in C or C++ 🔥. On most systems, those modules can be dynamically loaded. Python is also adaptable as an extension language for existing applications — see the internal documentation for hints, iykyk 👑

Want to read docs for installed Python modules and packages? Just run the pydoc program. that's it. that's the tip. 🌈

more parts coming bestie, don't go anywhere 💜

✨ COMMAND LINE OPTIONS ✨

Okay bestie, this is the part where the real fun starts — every single flag you can throw at python3. Grab a snack, we're going through all of them. 🍓

-B — bestie do NOT write .pyc files on import. That's it, that's the whole vibe. (Also peep PYTHONDONTWRITEBYTECODE if you want this energy everywhere.)
-b — throws warnings at you about str(bytes_instance), str(bytearray_instance), and comparing bytes/bytearray with str. Add another one — -bb — and it stops being a warning and becomes a whole error. Glow up. 💅
-c command — run the command you type in here (more on that in the next section, iykyk). Heads up: this ends the option list, so everything after it gets passed as arguments to your command. Lowkey important.
--check-hash-based-pycs mode — controls how Python decides whether hash-based .pyc files are up to date. Vibe check for your bytecode, basically.
-d — turns on parser debugging output. Experts only, and only if your build even has it compiled in. Not for the faint of heart fr.
-E — ignore environment variables like PYTHONPATH and PYTHONHOME that mess with how the interpreter behaves. Boundaries, periodt.
-h, -?, --help — prints the usage for the interpreter executable and dips. Classic.
--help-env — prints help about Python-specific environment variables and exits. 🧚
--help-xoptions — prints help about implementation-specific -X options and exits.
--help-all — prints the complete usage information and exits. The full lore drop.
-i — when a script is passed as the first argument, or you used -c, this drops you into interactive mode after the script or command runs. It does not read the $PYTHONSTARTUP file. Absolute lifesaver for inspecting global variables or getting a stack trace when a script raises an exception. 👑
-I — isolated mode, babes. This implies -E, -P and -s. In isolated mode, sys.path contains neither the script's directory nor the user's site-packages directory. All PYTHON* environment variables are ignored too. And honestly? Further restrictions may be imposed to stop the user from injecting malicious code. She's locked down. 🔥
-m module-name — searches sys.path for the module you named and runs the matching .py file as a script. Just like -c, this terminates the option list — everything after gets passed as arguments to the module.
-O — removes assert statements and any code conditional on the value of __debug__; it also augments the filename for compiled (bytecode) files by adding .opt-1 before the .pyc extension.
-OO — does everything -O does AND discards docstrings; changes the compiled (bytecode) filename by adding .opt-2 before the .pyc extension. Double stripped. 💀
-P — don't automatically prepend a potentially unsafe path to sys.path, like the current directory, the script's directory, or an empty string. See also the PYTHONSAFEPATH environment variable.
-q — do not print the version and copyright messages. (They're suppressed in non-interactive mode anyway, so consider this your quiet luxury era.)
-R — turn on hash randomization. Ngl this only does anything if PYTHONHASHSEED is set to 0, because hash randomization is already enabled by default. Iconic but mostly ceremonial.
-s — don't add the user site directory to sys.path.
-S — disable the import of the module site and the site-dependent manipulations of sys.path that come with it. And yes, it also disables those manipulations if site gets explicitly imported later.
-u — force the stdout and stderr streams to be unbuffered. Quick note: this has no effect on the stdin stream.
-v — prints a message every time a module is initialized, showing the place (filename or built-in module) from which it's loaded. Give it twice and you get a message for every single file checked while searching for a module. It also spills the tea on module cleanup at exit. So chatty, we love her. 🫶
-V, --version — prints the Python version number of the executable and exits. Give it twice and you get more information about the build.
-W argument — warning control. Python's warning machinery by default prints warning messages to sys.stderr.

The simplest settings apply a particular action unconditionally to all warnings emitted by a process (even those that are otherwise ignored by default):

-Wdefault  # Warn once per call location
-Werror    # Convert to exceptions
-Walways   # Warn every time
-Wall      # Same as -Walways
-Wmodule   # Warn once per calling module
-Wonce     # Warn once per Python process
-Wignore   # Never warn

The action names can be abbreviated however you want and the interpreter will resolve them to the appropriate action name. For example, -Wi is the same as -Wignore.

The full form of argument is:

action:message:category:module:lineno

Empty fields match all values; trailing empty fields may be omitted. For example -W ignore::DeprecationWarning ignores all DeprecationWarning warnings.

The action field is as explained above but only applies to warnings that match the remaining fields.

The message field must match the start of the warning message; this match is case-insensitive.

The category field matches the warning category (ex: "DeprecationWarning"). This must be a class name; the match tests whether the actual warning category of the message is a subclass of the specified warning category.

The module field matches the (fully-qualified) module name; this match is case-sensitive.

The lineno field matches the line number, where zero matches all line numbers and is thus equivalent to an omitted line number.

Multiple -W options can be given; when a warning matches more than one option, the action for the last matching option is performed. Invalid -W options are ignored (though, a warning message is printed about invalid options when the first warning is issued).

Warnings can also be controlled using the PYTHONWARNINGS environment variable and from within a Python program using the warnings module. For example, the warnings.filterwarnings() function can be used to use a regular expression on the warning message.

-X option — set an implementation-specific option. The following options are available:
- -X cpu_count=N — override the return value of os.cpu_count(). -X cpu_count=default cancels the overriding. See also PYTHON_CPU_COUNT.
- -X dev — enable CPython's "development mode", introducing additional runtime checks that are too expensive to be on by default. It will not be more verbose than the default if the code is correct: new warnings are only emitted when an issue is detected. Effect of the developer mode:
  - Add default warning filter, as -W default.
  - Install debug hooks on memory allocators: see the PyMem_SetupDebugHooks() C function.
  - Enable the faulthandler module to dump the Python traceback on a crash.
  - Enable asyncio debug mode.
  - Set the dev_mode attribute of sys.flags to True.
  - io.IOBase destructor logs close() exceptions.
- -X importtime — show how long each import takes. It shows module name, cumulative time (including nested imports) and self time (excluding nested imports). Note that its output may be broken in multi-threaded application. Typical usage is python3 -X importtime -c 'import asyncio'.

-X importtime=2 enables additional output that indicates when an imported module has already been loaded. In such cases, the string cached will be printed in both time columns.

-X faulthandler — enable faulthandler.
-X frozen_modules=[on|off] — whether or not frozen modules should be used. The default is "on" (or "off" if you are running a local build).
-X gil=[0|1] — enable (1) or disable (0) the GIL. See also PYTHON_GIL. Only available in builds configured with --disable-gil.
-X int_max_str_digits=number — limit the size of int↔str conversions. This helps avoid denial of service attacks when parsing untrusted data. The default is sys.int_info.default_max_str_digits. 0 disables.
-X no_debug_ranges — disable the inclusion of the tables mapping extra location information (end line, start column offset and end column offset) to every instruction in code objects. This is useful when smaller code objects and pyc files are desired, as well as suppressing the extra visual location indicators when the interpreter displays tracebacks.
-X perf — support the Linux "perf" profiler. See also PYTHONPERFSUPPORT=1.
-X perf_jit — support the Linux "perf" profiler with DWARF support. See also PYTHON_PERF_JIT_SUPPORT=1.
-X presite=MOD — import this module before site. See also PYTHON_PRESITE. This only works on debug builds.
-X pycache_prefix=PATH — enable writing .pyc files to a parallel tree rooted at the given directory instead of to the code tree.
-X showrefcount — output the total reference count and number of used memory blocks when the program finishes or after each statement in the interactive interpreter. This only works on debug builds.
-X tracemalloc — start tracing Python memory allocations using the tracemalloc module. By default, only the most recent frame is stored in a traceback of a trace. Use -X tracemalloc=NFRAME to start tracing with a traceback limit of NFRAME frames.
-X utf8 — enable UTF-8 mode for operating system interfaces, overriding the default locale-aware mode. -X utf8=0 explicitly disables UTF-8 mode (even when it would otherwise activate automatically). See PYTHONUTF8 for more details.
-X warn_default_encoding — enable opt-in EncodingWarning for 'encoding=None'.

-x — skip the first line of the source. This is intended for a DOS specific hack only.

⚠️ Warning bestie: with -x, the line numbers in error messages will be off by one! 😭 Keep that in mind before you go blaming the wrong line.

🌸 INTERPRETER INTERFACE 🌸

okay so bestie, the way the interpreter talks to you is literally giving UNIX shell energy, no cap. Here's the tea 🍵:

when you call it with standard input connected to a tty device, it prompts you for commands and executes them until it reads an EOF 🫶
when you call it with a file name argument, or with a file as standard input, it reads and executes a script from that file
when you call it with -c command, it executes the Python statement(s) given as command. and command can absolutely contain multiple statements separated by newlines 💅

⚠️ Leading whitespace is significant in Python statements! do not be out here deleting your indentation bestie, it WILL humble you 😭

also: in non-interactive mode, the entire input is parsed before it is executed. like, all of it, first, then it runs. that's just how it is 💖

if available, the script name and any additional arguments after it get passed to your script in the Python variable sys.argv, which is a list of strings (and yes you must first import sys to be able to access it, bestie, it's not just vibing in your namespace for free 🙈).

if no script name is given, sys.argv[0] is an empty string
if -c is used, sys.argv[0] contains the string '-c'

and heads up: options interpreted by the Python interpreter itself are not placed in sys.argv. they're not invited to that party ✨

in interactive mode, the primary prompt is >>>' and the second prompt (the one that shows up when a command is not complete) is ...'. you can change these prompts by assignment to sys.ps1 or sys.ps2 — main character customization, honestly 👑

the interpreter quits when it reads an EOF at a prompt. when an unhandled exception occurs, a stack trace is printed and control returns to the primary prompt 🌈. but in non-interactive mode, the interpreter exits after printing the stack trace. different vibes entirely.

the interrupt signal raises the KeyboardInterrupt exception 💀. other UNIX signals are not caught — except that SIGPIPE is sometimes ignored, in favor of the IOError exception.

error messages are written to stderr. that's just where they live 🎀

🎀 FILES AND DIRECTORIES 🎀

these are subject to difference depending on local installation conventions, so don't come for them if yours look different, bestie. ${prefix} and ${exec_prefix} are installation-dependent and should be interpreted as for GNU software; they may be the same 💜. the default for both is /usr/local.

${exec_prefix}/bin/python — recommended location of the interpreter. that's the one, the icon, the moment ⭐
${prefix}/lib/python<version>
${exec_prefix}/lib/python<version>

recommended locations of the directories containing the standard modules 📦

${prefix}/include/python<version>
${exec_prefix}/include/python<version>

recommended locations of the directories containing the include files needed for developing Python extensions and embedding the interpreter 🧚

✨ ENVIRONMENT VARIABLES ✨

okay this is the big one, the whole mood board of env vars. every single one, in order, no skipping 💅

PYTHONASYNCIODEBUG — if this environment variable is set to a non-empty string, enable the debug mode of the asyncio module 🦋
PYTHON_BASIC_REPL — if this variable is set to any value, the interpreter will not attempt to load the Python-based REPL that requires curses and readline, and will instead use the traditional parser-based REPL. retro vibes only 🔥
PYTHONBREAKPOINT — if this environment variable is set to 0, it disables the default debugger. it can be set to the callable of your debugger of choice 👑
PYTHONCOERCECLOCALE — if set to the value 0, causes the main Python command line application to skip coercing the legacy ASCII-based C and POSIX locales to a more capable UTF-8 based alternative 🌈
PYTHON_COLORS — if this variable is set to 1, the interpreter will colorize various kinds of output. setting it to 0 deactivates this behavior. color is a lifestyle 💖
PYTHON_CPU_COUNT — if this variable is set to a positive integer, it overrides the return values of os.cpu_count and os.process_cpu_count.

🐛 Debug-mode variables 🐛

important bestie: setting these only does anything in a debug build of Python — meaning Python was configured with the --with-pydebug build option. Regular build? They're just sitting there, unbothered, doing nothing. 💀

PYTHONDUMPREFS — set it and Python dumps all the objects and reference counts that are still alive after the interpreter shuts down. Spilling the tea on leaked refs. 🫖
PYTHONDUMPREFSFILE — same idea, but it dumps those still-alive objects and reference counts into a file located under the path you give as the value of this variable. Now the tea's in writing. 📝
PYTHON_PRESITE — set this to a module and that module gets imported early in the interpreter lifecycle: before the site module executes, and before the __main__ module is even created. Only works on debug builds, as established. ✨

This one is equivalent to the -X presite=module option. 🪄

👑 AUTHOR 👑

The Python Software Foundation: https://www.python.org/psf/

🌈 INTERNET RESOURCES 🌈

Main website: https://www.python.org/
Documentation: https://docs.python.org/
Developer resources: https://devguide.python.org/
Downloads: https://www.python.org/downloads/
Module repository: https://pypi.org/
Newsgroups: comp.lang.python, comp.lang.python.announce

📜 LICENSING 📜

Python is distributed under an Open Source license. Wanna know the terms & conditions for accessing and otherwise using Python, plus a DISCLAIMER OF ALL WARRANTIES? Check the file "LICENSE" in the Python source distribution. Go read it, bestie, it's giving responsible. 🫶

and that's the whole PYTHON(1) page, bestie 💖 the little footer at the bottom just said PYTHON(1) (y'know, the section 1 man page, which is where all the user commands live) — so if you ever see that tag floating at the end of your man python, that's this page, telling you it's from the Python manual. Now go write something iconic with it. periodt. 💅🎀🦋

📦 where this page comes from

alpine 3.24: python3-doc 3.14.10-r1 · PSF-2.0
arch rolling: python 3.14.8-1
arch rolling: python 3.14.9-1 · PSF-2.0
fedora 43: python3 3.14.8-1.fc43 · Python-2.0.1
fedora 43: python3 3.14.8-1.fc43 · Python-2.0.1
fedora 44: python3 3.14.8-1.fc44 · Python-2.0.1
fedora 44: python3 3.14.8-1.fc44 · Python-2.0.1
nixos 26.05: python3 3.15.0
nixpkgs unstable: python3-minimal 3.14.8
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-10-18: a language model's rewrite of the original, under its terms