Use unidecode as an API and allow alternatives (#53)

This PR allows specifying WITH_TEXTUNIDECODE when
installing python-slugify. This allows using
text-unidecode instead of unidecode. It will default
to using unidecode.

Closes: #51

5 files changed, 30 insertions, 4 deletions

diff --git a/.travis.yml b/.travis.yml
index d852b0a..737fa21 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,9 +10,13 @@ python:
   - "3.6"
   - pypy
 
+env:
+  - WITH_TEXTUNIDECODE=yes
+  - WITH_UNIDECODE=yes # this is redundant but otherwise travis will only trigger one build type
+
 install:
   - pip install pip -U
-  - pip install -q -r requirements.txt
+  - if [[ -z "${WITH_TEXTUNIDECODE}" ]]; then pip install -q -r requirements.txt; else pip install -q -r alt_requirements.txt; fi
   - pip install -e .
   - pip install pep8
   - pip install coveralls
diff --git a/README.rst b/README.rst
index a5a62ac..29b6e27 100644
--- a/README.rst
+++ b/README.rst
@@ -211,3 +211,19 @@ X.Y.Z Version
     :target: https://pypi.python.org/pypi/python-slugify
 
 .. _MIT: https://github.com/un33k/python-slugify/blob/master/LICENSE
+
+
+GPL
+---
+
+By default python-slugify depends on **unidecode** which is released under GPL. In case this is
+a concern to you it is possible to install slugify with **text-unidecode** which is dual licensed
+Perl Artistic and GPL. This can be done by:
+
+.. code:: bash
+    
+    $ export WITH_TEXTUNIDECODE=yes
+
+And then proceed with the normal installation instructions. Please note that this needs to be specified
+for every upgrade. Also be aware that in case **unidecode* is present on the system python-slugify will
+still default to using it.
diff --git a/alt_requirements.txt b/alt_requirements.txt
new file mode 100644
index 0000000..980e50a
--- /dev/null
+++ b/alt_requirements.txt
@@ -0,0 +1 @@
+text-unidecode>=1.2
\ No newline at end of file
diff --git a/setup.py b/setup.py
index abfaa3f..dcf21df 100755
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,10 @@ url = 'https://github.com/un33k/python-slugify'
 author = 'Val Neekman'
 author_email = 'info@neekware.com'
 license = 'MIT'
-install_requires = ['Unidecode>=0.04.16']
+if "WITH_TEXTUNIDECODE" in os.environ:
+    install_requires = ['text-unidecode>=1.2']
+else:
+    install_requires = ['Unidecode>=0.04.16']
 classifiers = [
     'Development Status :: 5 - Production/Stable',
     'Intended Audience :: Developers',
diff --git a/slugify/slugify.py b/slugify/slugify.py
index af0c609..8619184 100644
--- a/slugify/slugify.py
+++ b/slugify/slugify.py
@@ -13,8 +13,10 @@ except ImportError:
     _unicode_type = str
     unichr = chr
 
-import unidecode
-
+try:
+    import unidecode
+except ImportError:
+    import text_unidecode as unidecode
 
 __all__ = ['slugify', 'smart_truncate']