---
name: "fades"
section: "1"
platform: "linux"
package: "fades"
version: "9.0.2-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/fades"
---

# fades(1)

A system that automatically handles the virtualenvs in the cases normally found when writing scripts and simple programs, and even helps to administer big projects.

## NAME

fades - A system that automatically handles the virtualenvs in the cases normally found when writing scripts and simple programs, and even helps to administer big projects.

## SYNOPSIS

**fades** \[**-h**\]\[**--help**\] \[**-V**\]\[**--version**\] \[**-v**\]\[**--verbose**\] \[**-q**\]\[**--quiet**\] \[**-i**\]\[**--ipython**\] \[**-d**\]\[**--dependency**\] \[**-r**\]\[**--requirement**\] \[**-x**\]\[**--exec**\] \[**-p** *version*\]\[**--python**=*version*\] \[**--rm**=*UUID*\] \[**--system-site-packages**\] \[**--virtualenv-options**=*options*\] \[**--pip-options**=*options*\] \[**--python-options**=*options*\] \[**--check-updates**\] \[**--clean-unused-venvs**=*max\_days\_to\_keep*\] \[**--get-venv-dir**\] \[**--no-precheck-availability**\] \[**-a**\]\[**--autoimport**\] \[**--freeze**\] \[**-m**\]\[**--module**\] \[**--avoid-pip-upgrade**\] \[child\_program \[child\_options\]\]

**fades** can be used to execute directly your script, or put it with a #! at your script's beginning.

## DESCRIPTION

**fades** will automagically create a new virtualenv (or reuse a previous created one), installing the necessary dependencies, and execute your script inside that virtualenv, with the only requirement of executing the script with **fades** and also marking the required dependencies.

The first non-option parameter (if any) would be then the child program to execute, and any other parameters after that are passed as is to that child script.

**fades** can also be executed without passing a child script to execute: in this mode it will open a Python interactive interpreter inside the created/reused virtualenv (taking dependencies from *--dependency* or *--requirement* options). If *--autoimport* is given, it will automatically import all the installed dependencies.

If the *child\_program* parameter is really an URL, the script will be automatically downloaded from there (supporting also the most common pastebins URLs: pastebin.com, linkode.org, gist, etc.).

## OPTIONS

- **-h**, **--help**

  Show help about all the parameters and options, and quit.

- **-V**, **--version**

  Show the program version and info about the system, and quit.

- **-v**, **--verbose**

  Send all internal debugging lines to stderr, which may be very useful if any problem arises.

- **-q**, **--quiet**

  Don't show anything (unless it has a real problem), so the original script stderr is not polluted at all.

- **-i**, **--ipython**

  Runs IPython shell instead of python ones.

- **-d**, **--dependency**

  Specify dependencies through command line. This option can be specified multiple times (once per dependency), and each time the format is **repository::dependency**. The dependency may have versions specifications, and the repository is optional (it will infer it). Examples:

      requests\
       pypi::requests \> 2.3\
       requests\<=3\
       git+https://github.com/kennethreitz/requests.git#egg=requests\
       vcs::git+https://github.com/kennethreitz/requests.git#egg=requests

  See more examples below for real command line usage explanations.

- **-r**, **--requirement**

  Read the dependencies from a file. Format in each line is the same than dependencies specified with *--dependency*. This option can be specified multiple times.

- **-p** ***version***, **--python=*version***

  Select which Python version to be used; the argument can be just the number (2.7), the whole name (python2.7) or the whole path (/usr/bin/python2.7).  Of course, the corresponding version of Python needs to be installed in your system.

  The dependencies can be indicated in multiple places (in the Python source file, with a comment besides the import, in a *requirements*file, and/or through command line. In case of multiple definitions of the same dependency, command line overrides everything else, and requirements file overrides what is specified in the source code.

- **-x**, **--exec**

  Execute the *child\_program* in the context of the virtualenv. The child\_program, which in this case becomes a mandatory parameter, can be just the executable name (relative to the venv's bin directory) or an absolute path.

- **--rm** ***UUID***

  Remove a virtualenv by UUID.  See **--get-venv-dir** option to easily find out the UUID.

- **--system-site-packages**

  Give the virtual environment access to thesystem site-packages dir

- **--virtualenv-options=*VIRTUALENV\_OPTION***

  Extra options to be supplied to virtualenv. (this option can be used multiple times)

- **--pip-options=*PIP\_OPTION***

  Extra options to be supplied to pip. (this option can be used multiple times)

- **--python-options=*PYTHON\_OPTION***

  Extra options to be supplied to python. (this option can be used multiple times)

- **--check-updates**

  Will check for updates in PyPI to verify if there are new versions for the requested dependencies. If a new version is available for a dependency, it will use it (if the dependency was requested without version) or just inform which new version is available (if the dependency was requested with a specific version).

- **--clean-unused-venvs=*MAX\_DAYS\_TO\_KEEP***

  Will remove all virtualenvs that haven't been used for more than MAX\_DAYS\_TO\_KEEP days.

- **--get-venv-dir**

  Show the virtualenv base directory (which includes the virtualenv UUID) and quit.

- **--no-precheck-availability**

  Don't check if the packages exists in PyPI before actually try to install them.

- **-a**, **--autoimport**

  Automatically import the dependencies when in interactive interpreter mode (ignored otherwise).

- **--freeze** ***FILEPATH***

  Will operate exactly as without the command, but also it will dump the revisions of installed dependencies to the given **filepath**.

- **-m**, **--module**

  Run library module as a script (same behaviour than Python's **-m** parameter).

- **--avoid-pip-upgrade**

  Disable the automatic **pip** upgrade that happens after the virtualenv is created and before the dependencies begin to be installed.

## EXAMPLES

- fades foo.py --bar

  Executes foo.py under fades, passing the --bar parameter to the child program, in a virtualenv with the dependencies indicated in the source code.

- fades -v foo.py

  Executes foo.py under fades, showing all the fades messages (verbose mode).

- fades -d dependency1 -d dependency2\>3.2 foo.py --bar

  Executes foo.py under fades (passing the --bar parameter to it), in a virtualenv with the dependencies indicated in the source code and also dependency1 and dependency2 (any version \> 3.2).

- fades -d dependency1

  Executes the Python interactive interpreter in a virtualenv with dependency1 installed.

- fades -r requirements.txt

  Executes the Python interactive interpreter in a virtualenv after installing there all dependencies taken from the requirements.txt file.

- fades -r requirements.txt -r requirements\_devel.txt

  Executes the Python interactive interpreter in a virtualenv after installing there all dependencies taken from files requirements.txt and requirements\_devel.txt.

## USING CONFIGURATION FILES

You can also configure fades using **.ini** config files. fades will search config files in  **/etc/fades/fades.ini**, the path indicated by **xdg** for your system  (for example ~/config/fades/fades.ini) and .fades.ini.  So you can have different settings at system, user and project level.

The config files are in .ini format. (configparser) and fades will search for a \[fades\] section. You have to use the same configurations that in the CLI. The only difference is with the config  options with a dash, it has to be replaced with a underscore.

Check http://fades.readthedocs.org/en/latest/readme.html#setting-options-using-config-files for full examples.

## SEE ALSO

Development is centralized in https://github.com/PyAr/fades

Check that site for a better explanation of **fades** usage.

## AUTHORS

Facundo Batista, Nicolás Demarchi (see development page for contact info).

## LICENSING

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License version 3, as published by the Free Software Foundation.