Simplify setup.py and remove unecessary warning.

Fix #70

Author: mgautierfr

setup.py

@@ -15,95 +15,99 @@
 
 To compile or run this project, you must first get the libzim headers & binary:
 
- - You can get the headers here and build and install the binary from source:
-   https://github.com/openzim/libzim
-
- - Or you can download a full prebuilt release (if one exists for your platform):
+ - Compile and install libzim from source : https://github.com/openzim/libzim
+ - Download a full prebuilt release (if one exists for your platform):
    https://download.openzim.org/release/libzim/
+ - Installed a packaged version of libzim :
+   . `apt-get install libzim-devel`
+   . `dnf install libzim-dev`
 
 Either place the `libzim.so` and `zim/*.h` files in `./lib/` and `./include/`,
    or set these environment variables to use custom libzim header and dylib paths:
 
  $ export CFLAGS="-I/tmp/libzim_linux-x86_64-6.1.1/include"
  $ export LDFLAGS="-L/tmp/libzim_linux-x86_64-6.1.1/lib/x86_64-linux-gnu"
  $ export LD_LIBRARY_PATH+=":/tmp/libzim_linux-x86_64-6.1.1/lib/x86_64-linux-gnu"
+
+If you have installed libzim from the packages, you probably don't have anything to do
+on environment variables side.
 """
+
+
 import os
+import sys
 import platform
 from pathlib import Path
 from ctypes.util import find_library
+from textwrap import dedent
 
 from setuptools import setup, Extension
 from Cython.Build import cythonize
 from Cython.Distutils.build_ext import new_build_ext as build_ext
 
-BASE_DIR = Path(__file__).parent
-LIBZIM_INCLUDE_DIR = "include"  # the libzim C++ header src dir (containing zim/*.h)
-LIBZIM_LIBRARY_DIR = "lib"  # the libzim .so binary lib dir (containing libzim.so)
-LIBZIM_DYLIB = "libzim.{ext}".format(
-    ext="dylib" if platform.system() == "Darwin" else "so"
-)
-# set PROFILE env to `1` to enable profile info on build (used for coverage reporting)
-PROFILE = os.getenv("PROFILE", "") == "1"
+base_dir = Path(__file__).parent
 
+# Check if we need profiling (env var PROFILE set to `1`, used for coverage reporting)
+compiler_directives = {"language_level": "3"}
+if os.getenv("PROFILE", "") == "1":
+    define_macros = [("CYTHON_TRACE", "1"), ("CYTHON_TRACE_NOGIL", "1")]
+    compiler_directives.update(linetrace=True)
+else:
+    define_macros = []
 
-class fixed_build_ext(build_ext):
-    """Workaround for rpath bug in distutils for OSX."""
+if platform.system() == "Darwin":
+    class fixed_build_ext(build_ext):
+        """Workaround for rpath bug in distutils for OSX."""
 
-    def finalize_options(self):
-        super().finalize_options()
-        # Special treatment of rpath in case of OSX, to work around python
-        # distutils bug 36353. This constructs proper rpath arguments for clang.
-        # See https://bugs.python.org/issue36353
-        if platform.system() == "Darwin":
+        def finalize_options(self):
+            super().finalize_options()
+            # Special treatment of rpath in case of OSX, to work around python
+            # distutils bug 36353. This constructs proper rpath arguments for clang.
+            # See https://bugs.python.org/issue36353
             for path in self.rpath:
                 for ext in self.extensions:
                     ext.extra_link_args.append("-Wl,-rpath," + path)
             self.rpath[:] = []
-
+    cmdclass={"build_ext": fixed_build_ext}
+    dyn_lib_ext = "dylib"
+else:
+    cmdclass={"build_ext": build_ext}
+    dyn_lib_ext = "so"
 
 include_dirs = ["libzim"]
 library_dirs = []
 # Check for the CPP Libzim library headers in expected directory
-if (BASE_DIR / LIBZIM_INCLUDE_DIR / "zim" / "zim.h").exists() and
-   (BASE_DIR / LIBZIM_LIB_DIR / LIBZIM_DYLIB).exists():
-    print(
-        f"Found lizim library and headers in local directory.\n"
-        f"We will use them to compile python-libzim.\n"
-        f"Hint : If you don't want to use them (and use \"system\" installed one), remove them."
-    )
+if (base_dir / "include" / "zim" / "zim.h").exists() and (base_dir / "lib" / f"libzim.{dyn_lib_ext}").exists():
+    print(dedent("""\
+        Found lizim library and headers in local directory.
+        We will use them to compile python-libzim.
+        Hint : If you don't want to use them (and use "system" installed one), remove them.
+    """))
     include_dirs.append("include")
     library_dirs = ["lib"]
 else:
     # Check for library.
     if not find_library("zim"):
-        print(
-            "[!] The libzim library cannot be found.\n"
-            "Please verify that the library is correctly installed of and can be found."
-        )
+        print(dedent("""\
+            "[!] The libzim library cannot be found.
+            "Please verify that the library is correctly installed of and can be found.
+        """))
         sys.exit(1)
     print("Using system installed library. We are assuming CFLAGS/LDFLAGS are correctly set.")
 
-
 wrapper_extension = Extension(
     name="libzim",
     sources=["libzim/libzim.pyx", "libzim/libwrapper.cpp"],
-    include_dir=include_dirs,
+    include_dirs=include_dirs,
     libraries=["zim"],
     library_dirs=library_dirs,
     extra_compile_args=["-std=c++11", "-Wall", "-Wextra"],
     language="c++",
-    define_macros=[("CYTHON_TRACE", "1"), ("CYTHON_TRACE_NOGIL", "1")]
-    if PROFILE
-    else [],
+    define_macros=define_macros,
 )
 
-compiler_directives = {"language_level": "3"}
-if PROFILE:
-    compiler_directives.update({"linetrace": "True"})
-
 setup(
     # Content
-    cmdclass={"build_ext": fixed_build_ext},
+    cmdclass=cmdclass,
     ext_modules=cythonize([wrapper_extension], compiler_directives=compiler_directives),
 )