Support Graphviz installed from Conda

Graphviz installed using Conda is using .bat scripts
to correctly setup running it on Windows.

Author: prmtl

pydot_ng/__init__.py

@@ -398,6 +398,25 @@ def graph_from_incidence_matrix(matrix, node_prefix='', directed=False):
     return graph
 
 
+def is_quoted(path):
+    return path.startswith('"') and path.endswith('"')
+
+
+def is_windows():
+    return os.name == 'nt'
+
+
+def is_anacoda():
+    return os.path.exists(os.path.join(sys.prefix, 'conda-meta'))
+
+
+def get_executable_extension():
+    if is_windows():
+        return '.bat' if is_anacoda() else '.exe'
+    else:
+        return ''
+
+
 def __find_executables(path):
     """Used by find_graphviz
 
@@ -409,7 +428,8 @@ def __find_executables(path):
     Otherwise returns None
     """
 
-    success = False
+    any_found = False
+
     progs = {
         "dot": "",
         "twopi": "",
@@ -419,11 +439,12 @@ def __find_executables(path):
         "sfdp": "",
     }
 
-    was_quoted = False
     path = path.strip()
-    if path.startswith('"') and path.endswith('"'):
+    path_template = "{}"
+
+    if is_quoted(path):
         path = path[1:-1]
-        was_quoted = True
+        path_template = "\"{}\""
 
     if not os.path.isdir(path):
         return None
@@ -432,22 +453,14 @@ def __find_executables(path):
         if progs[prg]:
             continue
 
-        prg_path = os.path.join(path, prg)
-        prg_exe_path = prg_path + ".exe"
+        ext = get_executable_extension()
+        prg_path = os.path.join(path, prg + ext)
 
         if os.path.exists(prg_path):
-            if was_quoted:
-                prg_path = "\"{}\"".format(prg_path)
-            progs[prg] = prg_path
-            success = True
-
-        elif os.path.exists(prg_exe_path):
-            if was_quoted:
-                prg_exe_path = "\"{}\"".format(prg_exe_path)
-            progs[prg] = prg_exe_path
-            success = True
-
-    if success:
+            any_found = True
+            progs[prg] = path_template.format(prg_path)
+
+    if any_found:
         return progs
 
     return None

test/test_find_executables.py

@@ -0,0 +1,81 @@
+import mock
+import pytest
+
+import pydot_ng as pydot
+
+
+def touch(path):
+    f = open(path, "w")
+    f.close()
+
+
+def test_find_executables_fake_path():
+    assert pydot.__find_executables("/fake/path/") is None
+
+
+def test_find_executables_real_path_no_programs(tmpdir):
+    assert pydot.__find_executables(str(tmpdir)) is None
+
+
+def test_find_executables_path_needs_strip(tmpdir):
+    path = tmpdir.mkdir("subdir")
+    prog_path = str(path.join("dot"))
+
+    path_with_spaces = "    {}     ".format(path)
+
+    with open(prog_path, "w"):
+        progs = pydot.__find_executables(path_with_spaces)
+        assert progs["dot"] == prog_path
+        assert sorted(
+            ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
+        ) == sorted(progs)
+
+
+@pytest.mark.parametrize("quoted", (True, False), ids=("quoted", "unqoted"))
+@pytest.mark.parametrize(
+    "windows,conda,extension",
+    (
+        (True, True, "bat"),
+        (True, False, "exe"),
+        (False, False, "unix"),
+        (False, True, "unix"),
+    ),
+)
+@pytest.mark.parametrize(
+    "program", ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
+)
+@mock.patch.object(pydot, "is_anacoda")
+@mock.patch.object(pydot, "is_windows")
+def test_f_e(
+    mock_win, mock_conda, tmpdir, windows, conda, extension, program, quoted
+):
+    path = tmpdir.mkdir("PYDOT is_da best!")
+
+    mock_win.return_value = windows
+    mock_conda.return_value = conda
+
+    unix_path = str(path.join(program))
+    touch(unix_path)
+
+    exe_path = str(path.join(program + ".exe"))
+    touch(exe_path)
+
+    bat_path = str(path.join(program + ".bat"))
+    touch(bat_path)
+
+    if quoted:
+        path = '"{}"'.format(path)
+        unix_path = '"{}"'.format(unix_path)
+        bat_path = '"{}"'.format(bat_path)
+        exe_path = '"{}"'.format(exe_path)
+
+    progs = pydot.__find_executables(str(path))
+
+    if extension == "bat":
+        assert progs[program] == bat_path
+    elif extension == "exe":
+        assert progs[program] == exe_path
+    elif extension == "unix":
+        assert progs[program] == unix_path
+    else:
+        raise Exception("Unknown extension {}".format(extension))

test/test_pydot.py

@@ -8,8 +8,8 @@
 import warnings
 from textwrap import dedent
 
-import mock
 import pytest
+import mock
 
 import pydot_ng as pydot
 
@@ -279,58 +279,3 @@ def test_dotparser_import_warning():
             del sys.modules["pydot_ng"]
             warnings.simplefilter("always")
             import pydot_ng  # noqa: F401
-
-
-def test_find_executables_fake_path():
-    assert pydot.__find_executables("/fake/path/") is None
-
-
-def test_find_executables_real_path_no_programs(tmpdir):
-    assert pydot.__find_executables(str(tmpdir)) is None
-
-
-def test_find_executables_path_needs_strip(tmpdir):
-    path = tmpdir.mkdir("subdir")
-    prog_path = str(path.join("dot"))
-
-    path_with_spaces = "    {}     ".format(path)
-
-    with open(prog_path, "w"):
-        progs = pydot.__find_executables(path_with_spaces)
-        assert progs["dot"] == prog_path
-        assert sorted(
-            ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
-        ) == sorted(progs)
-
-
-def test_find_executables_unix_and_exe_exists(tmpdir):
-    path = str(tmpdir)
-    prog_unix_path = str(tmpdir.join("dot"))
-    prog_exe_path = str(tmpdir.join("dot.exe"))
-
-    with open(prog_unix_path, "w"):
-        with open(prog_exe_path, "w"):
-            progs = pydot.__find_executables(path)
-            assert progs["dot"] == prog_unix_path
-            assert progs["dot"] != prog_exe_path
-
-
-@pytest.mark.parametrize("quoted", (True, False), ids=("quoted", "unqoted"))
-@pytest.mark.parametrize("extension", ("", ".exe"))
-@pytest.mark.parametrize(
-    "program", ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
-)
-def test_find_executables(tmpdir, program, extension, quoted):
-    path = tmpdir.mkdir("PYDOT is_da best!")
-    prog_path = str(path.join(program + extension))
-
-    with open(prog_path, "w"):
-        if quoted:
-            path = "\"{}\"".format(path)
-            prog_path = "\"{}\"".format(prog_path)
-
-        progs = pydot.__find_executables(str(path))
-        assert progs[program] == prog_path
-        assert sorted(
-            ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
-        ) == sorted(progs)