Add requirements.txt support. Mint 1.0.0.dev0.

Adds requirements.txt support, fixing pex-tool#5.  This introduces backwards incompatible changes
with pre-1.0 versions.

Author: wickman

CHANGES.rst

@@ -2,6 +2,19 @@
 CHANGES
 =======
 
+----------
+1.0.0.dev0
+----------
+
+* Adds a number of flag aliases to be more compatible with pip command lines: ``--no-index``,
+  ``-f``, ``--find-links``, ``--index-url``, ``--no-use-wheel``.  Removes ``-p`` in favor of
+  ``-o`` exclusively.
+
+* BREAKING CHANGE: ``pex -r`` now takes requirements.txt filenames and *not* requirement
+  specs.  Requirement specs are now passed as arguments to the pex tool.  Use ``--`` to escape
+  command line arguments passed to interpreters spawned by pex.  Implements
+  `#5 <https://github.com/pantsbuild/pex/issues/5>`_.
+
 -----
 0.9.0
 -----

README.rst

@@ -49,32 +49,38 @@ Launch an interpreter with ``requests`` and ``flask`` in the environment:
 
 .. code-block:: bash
 
-    $ pex -r requests -r flask
+    $ pex requests flask
+
+Or instead launch an interpreter with the requirements from requirements.txt:
+
+.. code-block:: bash
+
+    $ pex -r requirements.txt
 
 Run webserver.py in an environment containing ``flask`` and the setup.py package in
 the current working directory:
 
 .. code-block::
 
-    $ pex -r flask -s . -- webserver.py
+    $ pex flask -s . -- webserver.py
 
 Launch Sphinx in an ephemeral pex environment using the Sphinx entry point ``sphinx:main``:
 
 .. code-block:: bash
 
-    $ pex -r sphinx -e sphinx:main -- --help
+    $ pex sphinx -e sphinx:main -- --help
 
 Build a standalone pex binary into ``pex.pex``:
 
 .. code-block::
 
-    $ pex -r pex -e pex.bin.pex:main -o pex.pex
+    $ pex pex -e pex.bin.pex:main -o pex.pex
 
 Build a standalone pex binary but invoked using a specific Python version:
 
 .. code-block::
 
-    $ pex -r pex -e pex.bin.pex:main --python=pypy -o pypy-pex.pex
+    $ pex pex -e pex.bin.pex:main --python=pypy -o pypy-pex.pex
 
 Most pex options compose well with one another, so the above commands can be
 mixed and matched.

docs/buildingpex.rst

@@ -44,10 +44,10 @@ Specifying requirements
 -----------------------
 
 Requirements are specified using the same form as expected by ``setuptools``, e.g. ``flask``, ``setuptools==2.1.2``,
-``Django>=1.4,<1.6``.  These are specified using the ``-r`` option and may be specified multiple times.  For example,
-to start an environment with ``flask`` and ``psutil>1``::
+``Django>=1.4,<1.6``.  These are specified as arguments to pex and any number (including 0) may be specified.
+For example, to start an environment with ``flask`` and ``psutil>1``::
 
-    $ pex -r flask -r 'psutil>1'
+    $ pex flask 'psutil>1'
     Python 2.6.9 (unknown, Jan  2 2014, 14:52:48)
     [GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)] on darwin
     Type "help", "copyright", "credits" or "license" for more information.
@@ -72,7 +72,7 @@ Entry points define how the environment is executed and may be specified using t
 As mentioned above, if no entry points are specified, the default behavior is to emulate an
 interpreter::
 
-    $ pex -r flask
+    $ pex flask
     Python 2.6.9 (unknown, Jan  2 2014, 14:52:48)
     [GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)] on darwin
     Type "help", "copyright", "credits" or "license" for more information.
@@ -92,7 +92,7 @@ Like an interpreter, if a source file is specified, it is invoked::
     > app.run()
     > EOF
 
-    $ pex -r flask -- ./flask_hello_world.py
+    $ pex flask -- ./flask_hello_world.py
     * Running on http://127.0.0.1:5000/
 
 As an example of using a non-empty entry point, consider the Python ``pydoc``
@@ -121,7 +121,7 @@ This can be emulated using the ``pex`` tool using ``-e pydoc``::
 Arguments will be passed unescaped following ``--`` on the command line.  So in order to
 get pydoc help on the ``flask.app`` package in Flask::
 
-    $ pex -r flask -e pydoc -- flask.app
+    $ pex flask -e pydoc -- flask.app
     Help on module flask.app in flask:
 
     NAME
@@ -142,7 +142,7 @@ and Fabric respectively.  This is roughly equivalent to running a script that do
 This can be a powerful way to invoke Python applications without ever having to ``pip install``
 anything, for example a one-off invocation of Sphinx with the readthedocs theme available::
 
-    $ pex -r sphinx -r sphinx_rtd_theme -e sphinx:main -- --help
+    $ pex sphinx sphinx_rtd_theme -e sphinx:main -- --help
     Sphinx v1.2.2
     Usage: /var/folders/4d/9tz0cd5n2n7947xs21gspsxc0000gp/T/tmpLr8ibZ [options] sourcedir outdir [filenames...]
 
@@ -163,7 +163,7 @@ exist for the duration of the pex command lifetime and immediately garbage colle
 If the ``-o PATH`` option is specified, a PEX file of the environment is saved to disk at ``PATH``.  For example
 we can package a standalone Sphinx as above::
 
-    $ pex -r sphinx -r sphinx_rtd_theme -e sphinx:main -o sphinx.pex
+    $ pex sphinx sphinx_rtd_theme -e sphinx:main -o sphinx.pex
 
 Instead of executing the environment, it is saved to disk::
 
@@ -188,7 +188,7 @@ As before, entry points are not required, and if not specified the PEX will defa
 an interpreter.  If an alternate interpreter is specified with ``--python``, e.g. pypy, it will be the
 default hashbang in the PEX file::
 
-    $ pex --python=pypy -r flask -o flask-pypy.pex
+    $ pex --python=pypy flask -o flask-pypy.pex
 
 The hashbang of the PEX file specifies PyPy::
 
@@ -208,17 +208,16 @@ and when invoked uses the environment PyPy::
 Tailoring requirement resolution
 --------------------------------
 
-By default, ``pex`` fetches artifacts from PyPI.  This can be disabled with ``--no-pypi`` and
-explicitly enabled with ``--pypi``.
+By default, ``pex`` fetches artifacts from PyPI.  This can be disabled with ``--no-index``.
 
-If PyPI fetching is disabled, you will need to specify a search repository via ``--repo``.  This
+If PyPI fetching is disabled, you will need to specify a search repository via ``-f/--find-links``.  This
 may be a directory on disk or a remote simple http server.
 
 For example, you can delegate artifact fetching and resolution to ``pip wheel`` for whatever
 reason -- perhaps you're running a firewalled mirror -- but continue to package with pex::
 
     $ pip wheel sphinx sphinx_rtd_theme
-    $ pex -r sphinx -r sphinx_rtd_theme -e sphinx:main --no-pypi --repo=wheelhouse -o sphinx.pex
+    $ pex sphinx sphinx_rtd_theme -e sphinx:main --no-index --find-links=wheelhouse -o sphinx.pex
 
 
 Tailoring PEX execution

pex/archiver.py

@@ -1,3 +1,6 @@
+# Copyright 2015 Pants project contributors (see CONTRIBUTORS.md).
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
 import contextlib
 import os
 import tarfile

pex/base.py

@@ -38,4 +38,4 @@ def maybe_requirement_list(reqs):
 
 
 def requirement_is_exact(req):
-  return req.specs and len(req.specs) == 1 and req.specs[0][0] == '=='
+  return bool(req.specs and len(req.specs) == 1 and req.specs[0][0] == '==')