Created --autoimport parameter to autoimport indicated dependencies.

README.rst

@@ -136,6 +136,21 @@ version)::
     import bs4   # fades beautifulsoup4 == 4.2
 
 
+What if no script is given to execute?
+--------------------------------------
+
+If no script or program is passed to execute, *fades* will provide a virtualenv 
+with all the indicated dependencies, and then open an interactive interpreter 
+in the context of that virtualenv.
+
+Here is where it comes very handy the ``-i/--ipython`` option, if that REPL
+is preferred over the standard one.
+
+In the case of using an interactive interpreter, it's also very useful to
+make *fades* to automatically import all the indicated dependencies, 
+passing the ``--autoimport`` parameter.
+
+
 Other ways to specify dependencies
 ----------------------------------
 

fades/main.py

@@ -25,11 +25,19 @@
 import sys
 import shlex
 import subprocess
+import tempfile
 
 import fades
-
-from fades import FadesError
-from fades import parsing, logger as fades_logger, cache, helpers, envbuilder, file_options
+from fades import (
+    FadesError,
+    cache,
+    envbuilder,
+    file_options,
+    helpers,
+    logger as fades_logger,
+    parsing,
+    pkgnamesdb,
+)
 
 # the signals to redirect to the child process (note: only these are
 # allowed in Windows, see 'signal' doc).
@@ -42,7 +50,7 @@
     signal.SIGTERM,
 ]
 
-help_epilog = """
+HELP_EPILOG = """
 The "child program" is the script that fades will execute. It's an
 optional parameter, it will be the first thing received by fades that
 is not a parameter.  If no child program is indicated, a Python
@@ -52,6 +60,58 @@
 parameters passed as is to the child program.
 """
 
+AUTOIMPORT_HEADER = """
+import sys
+print("Python {} on {}".format(sys.version, sys.platform))
+print('Type "help", "copyright", "credits" or "license" for more information.')
+"""
+
+AUTOIMPORT_MOD_IMPORTER = """
+try:
+    import {module}
+except ImportError:
+    print("::fades:: FAILED to autoimport {module!r}")
+else:
+    print("::fades:: automatically imported {module!r}")
+"""
+
+AUTOIMPORT_MOD_SKIPPING = (
+    """print("::fades:: autoimport skipped because not a PyPI package: {dependency!r}")\n""")
+
+
+def get_autoimport_scriptname(dependencies, is_ipython):
+    """Return the path of script that will import dependencies for interactive mode.
+
+    The script has:
+
+    - a safe import of the dependencies, taking in consideration that the module may be named
+      differently than the package, and printing a message accordingly
+
+    - if regular Python, also print the normal interactive interpreter first information lines,
+      that are not shown when starting it with `-i` (but IPython shows them anyway).
+    """
+    fd, tempfilepath = tempfile.mkstemp(prefix='fadesinit-', suffix='.py')
+    fh = os.fdopen(fd, 'wt', encoding='utf8')
+
+    if not is_ipython:
+        fh.write(AUTOIMPORT_HEADER)
+
+    for repo, dependencies in dependencies.items():
+        for dependency in dependencies:
+            if repo == fades.REPO_PYPI:
+                package = dependency.name
+                if is_ipython and package == 'ipython':
+                    # Ignore this artificially added dependency.
+                    continue
+
+                module = pkgnamesdb.PACKAGE_TO_MODULE.get(package, package)
+                fh.write(AUTOIMPORT_MOD_IMPORTER.format(module=module))
+            else:
+                fh.write(AUTOIMPORT_MOD_SKIPPING.format(dependency=dependency))
+
+    fh.close()
+    return tempfilepath
+
 
 def consolidate_dependencies(needs_ipython, child_program,
                              requirement_files, manual_dependencies):
@@ -171,7 +231,7 @@ def _get_normalized_args(parser):
 
 def go():
     """Make the magic happen."""
-    parser = argparse.ArgumentParser(prog='PROG', epilog=help_epilog,
+    parser = argparse.ArgumentParser(prog='PROG', epilog=HELP_EPILOG,
                                      formatter_class=argparse.RawDescriptionHelpFormatter)
     parser.add_argument('-V', '--version', action='store_true',
                         help="show version and info about the system, and exit")
@@ -223,6 +283,9 @@ def go():
     parser.add_argument('--get-venv-dir', action='store_true',
                         help=("Show the virtualenv base directory (which includes the "
                               "virtualenv UUID) and quit."))
+    parser.add_argument('-a', '--autoimport', action='store_true',
+                        help=("Automatically import the specified dependencies in the "
+                              "interactive mode (ignored otherwise)."))
     parser.add_argument('child_program', nargs='?', default=None)
     parser.add_argument('child_options', nargs=argparse.REMAINDER)
 
@@ -356,11 +419,17 @@ def go():
 
     # store usage information
     usage_manager.store_usage_stat(venv_data, venvscache)
+
     if child_program is None:
         interactive = True
-        logger.debug(
-            "Calling the interactive Python interpreter with arguments %r", python_options)
         cmd = [python_exe] + python_options
+
+        # get possible extra python options and environement for auto import
+        if indicated_deps and args.autoimport:
+            temp_scriptpath = get_autoimport_scriptname(indicated_deps, args.ipython)
+            cmd += ['-i', temp_scriptpath]
+
+        logger.debug("Calling the interactive Python interpreter: %s", cmd)
         p = subprocess.Popen(cmd)
     else:
         interactive = False

fades/parsing.py

@@ -23,7 +23,7 @@
 from pkg_resources import parse_requirements
 
 from fades import REPO_PYPI, REPO_VCS
-from fades.pkgnamesdb import PKG_NAMES_DB
+from fades.pkgnamesdb import MODULE_TO_PACKAGE
 
 logger = logging.getLogger(__name__)
 
@@ -130,7 +130,7 @@ def _parse_content(fh):
         if import_part.startswith('#'):
             continue
 
-        # get module
+        # Get the module.
         import_tokens = import_part.split()
         if import_tokens[0] == 'import':
             module_path = import_tokens[1]
@@ -140,17 +140,21 @@ def _parse_content(fh):
             logger.debug("Not understood import info: %s", import_tokens)
             continue
         module = module_path.split(".")[0]
-        # If fades know the real name of the pkg. Replace it!
-        if module in PKG_NAMES_DB:
-            module = PKG_NAMES_DB[module]
+
+        # The package has the same name (most of the times! if fades knows the conversion, use it).
+        if module in MODULE_TO_PACKAGE:
+            package = MODULE_TO_PACKAGE[module]
+        else:
+            package = module
+
         # To match the "safe" name that pkg_resources creates:
-        module = module.replace('_', '-')
+        package = package.replace('_', '-')
 
         # get the fades info after 'fades' mark, if any
         if len(fades_part) == 5 or fades_part[5:].strip()[0] in "<>=!":
             # just the 'fades' mark, and maybe a version specification, the requirement is what
             # was imported (maybe with that version comparison)
-            requirement = module + fades_part[5:]
+            requirement = package + fades_part[5:]
         elif fades_part[5] != " ":
             # starts with fades but it's part of a longer weird word
             logger.warning("Not understood fades info: %r", fades_part)

fades/pkgnamesdb.py

@@ -1,4 +1,4 @@
-# Copyright 2015 Facundo Batista, Nicolás Demarchi
+# Copyright 2015-2020 Facundo Batista, Nicolás Demarchi
 #
 # 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
@@ -14,14 +14,19 @@
 #
 # For further info, check  https://github.com/PyAr/fades
 
-"""A list of packages containing names which don't match with the PyPi distrbution's name."""
+"""A module to package and viceversa conversion DB.
 
-PKG_NAMES_DB = {
+This is needed for names which don't match with the distrbution's name.
+"""
+
+MODULE_TO_PACKAGE = {
     'bs4': 'beautifulsoup4',
     'github3': 'github3.py',
     'uritemplate': 'uritemplate.py',
     'postgresql': 'py-postgresql',
     'yaml': 'pyyaml',
-    'PIL': 'Pillow',
+    'PIL': 'pillow',
     'Crypto': 'pycrypto',
 }
+
+PACKAGE_TO_MODULE = {v: k for k, v in MODULE_TO_PACKAGE.items()}

man/fades.1

@@ -34,7 +34,7 @@ fades - A system that automatically handles the virtualenvs in the cases normall
 
 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.
 
-\fBfades\fR 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 \fI--dependency\fR or \fI--requirement\fR options).
+\fBfades\fR 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 \fI--dependency\fR or \fI--requirement\fR options). If \fI--autoimport\fR is given, it will automatically import all the installed dependencies.
 
 If the \fIchild_program\fR 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.).
 
@@ -126,6 +126,10 @@ Show the virtualenv base directory (which includes the virtualenv UUID) and quit
 .BR --no-precheck-availability
 Don't check if the packages exists in PyPI before actually try to install them.
 
+.TP
+.BR -a ", " --autoimport
+Automatically import the dependencies when in interactive interpreter mode (ignored otherwise).
+
 
 .SH EXAMPLES
 

testdev

@@ -10,4 +10,4 @@ else
     TARGET_TESTS=""
 fi
 
-./bin/fades -r requirements.txt -x pytest $TARGET_TESTS
+./bin/fades -r requirements.txt -x pytest -s $TARGET_TESTS

tests/test_main.py

@@ -22,7 +22,7 @@
 
 from pkg_resources import Requirement
 
-from fades import VERSION, FadesError, __version__, main, parsing
+from fades import VERSION, FadesError, __version__, main, parsing, REPO_PYPI, REPO_VCS
 from tests import create_tempfile
 
 
@@ -217,3 +217,81 @@ def test_indicated_with_executable_flag_in_path(self):
         """Absolute paths not allowed when using --exec."""
         with self.assertRaises(FadesError):
             main.decide_child_program(True, os.path.join("path", "foobar.py"))
+
+
+# ---------------------------------------
+# autoimport tests
+
+def _autoimport_safe_call(*args, **kwargs):
+    """Call the tested function and always remove the tempfile after the test."""
+    fpath = main.get_autoimport_scriptname(*args, **kwargs)
+
+    with open(fpath, "rt", encoding='utf8') as fh:
+        content = fh.read()
+    os.unlink(fpath)
+
+    return content
+
+
+def test_autoimport_simple():
+    """Simplest autoimport call."""
+    dependencies = {
+        REPO_PYPI: {Requirement.parse('mymod')},
+    }
+    content = _autoimport_safe_call(dependencies, is_ipython=False)
+
+    assert content.startswith(main.AUTOIMPORT_HEADER)
+    assert main.AUTOIMPORT_MOD_IMPORTER.format(module='mymod') in content
+
+
+def test_autoimport_several_dependencies():
+    """Indicate several dependencies."""
+    dependencies = {
+        REPO_PYPI: {Requirement.parse('mymod1'), Requirement.parse('mymod2')},
+    }
+    content = _autoimport_safe_call(dependencies, is_ipython=False)
+
+    assert content.startswith(main.AUTOIMPORT_HEADER)
+    assert main.AUTOIMPORT_MOD_IMPORTER.format(module='mymod1') in content
+    assert main.AUTOIMPORT_MOD_IMPORTER.format(module='mymod2') in content
+
+
+def test_autoimport_including_ipython():
+    """Call with ipython modifier."""
+    dependencies = {
+        REPO_PYPI: {
+            Requirement.parse('mymod'),
+            Requirement.parse('ipython'),  # this one is automatically added
+        },
+    }
+    content = _autoimport_safe_call(dependencies, is_ipython=True)
+
+    assert main.AUTOIMPORT_HEADER not in content
+    assert main.AUTOIMPORT_MOD_IMPORTER.format(module='mymod') in content
+    assert 'ipython' not in content
+
+
+def test_autoimport_no_pypi_dep():
+    """Case with no pypi dependencies."""
+    dependencies = {
+        REPO_PYPI: {Requirement.parse('my_pypi_mod')},
+        REPO_VCS: {'my_vcs_dependency'},
+    }
+    content = _autoimport_safe_call(dependencies, is_ipython=False)
+
+    assert main.AUTOIMPORT_MOD_IMPORTER.format(module='my_pypi_mod') in content
+    assert main.AUTOIMPORT_MOD_SKIPPING.format(dependency='my_vcs_dependency') in content
+
+
+def test_autoimport_importer_mod_ok(capsys):
+    """Check the generated code to import a module when works fine."""
+    code = main.AUTOIMPORT_MOD_IMPORTER.format(module='time')  # something from stdlib, always ok
+    exec(code)
+    assert capsys.readouterr().out == "::fades:: automatically imported 'time'\n"
+
+
+def test_autoimport_importer_mod_fail(capsys):
+    """Check the generated code to import a module when works fine."""
+    code = main.AUTOIMPORT_MOD_IMPORTER.format(module='not_there_should_explode')
+    exec(code)
+    assert capsys.readouterr().out == "::fades:: FAILED to autoimport 'not_there_should_explode'\n"

tests/test_pkgnamesdb.py

@@ -0,0 +1,24 @@
+# Copyright 2020 Facundo Batista, Nicolás Demarchi
+#
+# 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.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranties of
+# MERCHANTABILITY, SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR
+# PURPOSE.  See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# For further info, check  https://github.com/PyAr/fades
+
+"""Tests for the package names DB."""
+
+from fades import pkgnamesdb
+
+
+def test_db_consistency():
+    """Ensure multiple DB entrypoints are consistent between them."""
+    assert len(pkgnamesdb.MODULE_TO_PACKAGE) == len(pkgnamesdb.PACKAGE_TO_MODULE)