API: change add_basemap to not return the received ax object (#92)

add_basemap return None instead of ax

Author: jorisvandenbossche

contextily/plotting.py

@@ -76,12 +76,6 @@ def add_basemap(
     **extra_imshow_args : dict
                           Other parameters to be passed to `imshow`.
 
-    Returns
-    -------
-    ax                  : AxesSubplot
-                          Matplotlib axis with `x_lim` and `y_lim` set in Web
-                          Mercator (EPSG=3857) containing the basemap
-
     Example
     -------
 
@@ -91,15 +85,15 @@ def add_basemap(
     Add a web basemap:
 
     >>> ax = db.plot(alpha=0.5, color='k', figsize=(6, 6))
-    >>> ax = ctx.add_basemap(ax, url=url)
+    >>> ctx.add_basemap(ax, url=url)
     >>> plt.show()
 
     Or download a basemap to a local file and then plot it:
 
     >>> url = 'virginia.tiff'
     >>> _ = ctx.bounds2raster(*db.total_bounds, zoom=6, path=url)
     >>> ax = db.plot(alpha=0.5, color='k', figsize=(6, 6))
-    >>> ax = ctx.add_basemap(ax, url=url)
+    >>> ctx.add_basemap(ax, url=url)
     >>> plt.show()
 
     """
@@ -144,7 +138,9 @@ def add_basemap(
         bb = raster.bounds
         extent = bb.left, bb.right, bb.bottom, bb.top
     # Plotting
-    ax.imshow(image, extent=extent, interpolation=interpolation, **extra_imshow_args)
+    img = ax.imshow(
+        image, extent=extent, interpolation=interpolation, **extra_imshow_args
+    )
 
     if reset_extent:
         ax.axis((xmin, xmax, ymin, ymax))
@@ -157,7 +153,7 @@ def add_basemap(
     if attribution:
         add_attribution(ax, attribution, font_size=attribution_size)
 
-    return ax
+    return
 
 
 def _reproj_bb(left, right, bottom, top, s_crs, t_crs):

tests/test_ctx.py

@@ -241,7 +241,7 @@ def test_add_basemap():
     fig, ax = matplotlib.pyplot.subplots(1)
     ax.set_xlim(x1, x2)
     ax.set_ylim(y1, y2)
-    ax = ctx.add_basemap(ax, zoom=10)
+    ctx.add_basemap(ax, zoom=10)
 
     # ensure add_basemap did not change the axis limits of ax
     ax_extent = (x1, x2, y1, y2)
@@ -256,7 +256,7 @@ def test_add_basemap():
     ax.set_xlim(x1, x2)
     ax.set_ylim(y1, y2)
     loc = ctx.Place(SEARCH, path="./test2.tif", zoom_adjust=ADJUST)
-    ax = ctx.add_basemap(ax, url="./test2.tif")
+    ctx.add_basemap(ax, url="./test2.tif")
 
     raster_extent = (
         -11740803.981631357,
@@ -273,7 +273,7 @@ def test_add_basemap():
     f, ax = matplotlib.pyplot.subplots(1)
     ax.set_xlim(x1, x2)
     ax.set_ylim(y1, y2)
-    ax = ctx.add_basemap(ax, zoom="auto")
+    ctx.add_basemap(ax, zoom="auto")
 
     ax_extent = (
         -11740727.544603072,
@@ -292,7 +292,7 @@ def test_add_basemap():
     f, ax = matplotlib.pyplot.subplots(1)
     ax.set_xlim(x1, x2)
     ax.set_ylim(y1, y2)
-    ax = ctx.add_basemap(ax, crs={"init": "epsg:4326"}, attribution=None)
+    ctx.add_basemap(ax, crs={"init": "epsg:4326"}, attribution=None)
     assert ax.get_xlim() == (x1, x2)
     assert ax.get_ylim() == (y1, y2)
     assert ax.images[0].get_array().sum() == 724238693
@@ -303,9 +303,7 @@ def test_add_basemap():
     f, ax = matplotlib.pyplot.subplots(1)
     ax.set_xlim(x1, x2)
     ax.set_ylim(y1, y2)
-    ax = ctx.add_basemap(
-        ax, url="./test2.tif", crs={"init": "epsg:4326"}, attribution=None
-    )
+    ctx.add_basemap(ax, url="./test2.tif", crs={"init": "epsg:4326"}, attribution=None)
     assert ax.get_xlim() == (x1, x2)
     assert ax.get_ylim() == (y1, y2)
     assert ax.images[0].get_array().sum() == 724238693