Merge pull request #307 from audiolion/make-pandas-optional

Make pandas optional

.travis.yml

@@ -6,5 +6,5 @@ python:
   - 3.5
   - 3.6
 install:
-  - python setup.py install
+  - pip install -r requirements.txt
 script: python test_tablib.py

setup.py

@@ -48,7 +48,6 @@ install = [
     'xlrd',
     'xlwt',
     'pyyaml',
-    'pandas'
 ]
 
 
@@ -81,4 +80,7 @@ setup(
     ],
     tests_require=['pytest'],
     install_requires=install,
+    extras_require={
+        'pandas': ['pandas'],
+    },
 )

tablib/formats/_df.py

@@ -10,7 +10,10 @@ if sys.version_info[0] > 2:
 else:
     from cStringIO import StringIO as BytesIO
 
-from pandas import DataFrame
+try:
+    from pandas import DataFrame
+except ImportError:
+    DataFrame = None
 
 import tablib
 
@@ -21,6 +24,8 @@ extensions = ('df', )
 
 def detect(stream):
     """Returns True if given stream is a DataFrame."""
+    if DataFrame is None:
+        return False
     try:
         DataFrame(stream)
         return True
@@ -30,6 +35,10 @@ def detect(stream):
 
 def export_set(dset, index=None):
     """Returns DataFrame representation of DataBook."""
+    if DataFrame is None:
+        raise NotImplementedError(
+            'DataFrame Format requires `pandas` to be installed.'
+            ' Try `pip install tablib[pandas]`.')
     dataframe = DataFrame(dset.dict, columns=dset.headers)
     return dataframe