fix travis error

.travis.yml

@@ -16,6 +16,10 @@ env:
   - PYTHON_VERSION=3.6 BACKEND=agg
 
 before_install:
+  - mkidr -p ~/.xenonpy/dataset
+  - mkidr -p ~/.xenonpy/cached
+  - cp travis/*.pkl ~/.xenonpy/dataset/
+  - list ~/.xenonpy
   - cp travis/matplotlibrc_${BACKEND} matplotlibrc
   - if [ $BACKEND == "qtagg" ]; then
     export DISPLAY=:99.0;

travis/install.sh

@@ -9,9 +9,7 @@ wget https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -O mi
 bash miniconda.sh -b -p $HOME/miniconda
 export PATH="$HOME/miniconda/bin:$PATH"
 export MPLBACKEN='Agg'
-mkidr -p ~/.xenonpy/dataset
-mkidr -p ~/.xenonpy/cached
-cp travis/*.pkl ~/.xenonpy/dataset/
+
 hash -r
 conda config --set always_yes yes --set changeps1 no
 conda update -q conda

xenonpy/utils/datatools.py

@@ -121,14 +121,14 @@ def __init__(self, path: str = None, *,
         self.dataset_dir = Path().home() / __pkg_cfg_root__ / 'dataset'
         self.cached_dir = Path().home() / __pkg_cfg_root__ / 'cached'
 
-    def _fetch_data(self, url: str, save_to):
+    def _fetch_data(self, url, save_to):
 
         http = urllib3.PoolManager()
 
         # fetch `name.pkl` file
         try:
             r = http.request('GET', url, preload_content=False)
-            with open(save_to, 'wb') as out:
+            with open(str(save_to), 'wb') as out:
                 while True:
                     data = r.read(self.chunk_size)
                     if not data:
@@ -141,7 +141,7 @@ def _fetch_data(self, url: str, save_to):
         finally:
             r.release_conn()
 
-    def __call__(self, name: str, include=None, exclude=None):
+    def __call__(self, name, include=None, exclude=None):
         """
         load preset dataset.
 
@@ -236,7 +236,7 @@ class Saver(Iterator):
     """
     Save data in a convenient way::
 
-    .. code: pytho
+    .. code: python
 
         import numpy as np
         np.random.seed(0)