Use upper-case for constant name (Fix C0103)

Author: seisman

pygmt/datasets/tile_map.py

@@ -6,9 +6,9 @@
 try:
     import contextily
 
-    _has_contextily = True
+    _HAS_CONTEXTILY = True
 except ImportError:
-    _has_contextily = False
+    _HAS_CONTEXTILY = False
 
 import numpy as np
 import xarray as xr
@@ -110,7 +110,7 @@ def load_tile_map(region, zoom="auto", source=None, lonlat=True, wait=0, max_ret
       * x            (x) float64 -2.004e+07 -1.996e+07 ... 1.996e+07 2.004e+07
     """
     # pylint: disable=too-many-locals
-    if not _has_contextily:
+    if not _HAS_CONTEXTILY:
         raise ImportError(
             "Package `contextily` is required to be installed to use this function. "
             "Please use `python -m pip install contextily` or "

pygmt/figure.py

@@ -9,9 +9,9 @@
 try:
     import IPython
 
-    _has_ipython = True
+    _HAS_IPYTHON = True
 except ImportError:
-    _has_ipython = False
+    _HAS_IPYTHON = False
 
 
 from pygmt.clib import Session
@@ -35,7 +35,7 @@
 }
 
 # Show figures in Jupyter notebooks if available
-if _has_ipython:
+if _HAS_IPYTHON:
     get_ipython = IPython.get_ipython()  # pylint: disable=invalid-name
     if get_ipython and "IPKernelApp" in get_ipython.config:  # Jupyter Notebook enabled
         SHOW_CONFIG["method"] = "notebook"
@@ -454,7 +454,7 @@ def show(self, dpi=300, width=500, method=None, waiting=0.5, **kwargs):
             )
 
         if method == "notebook":
-            if not _has_ipython:
+            if not _HAS_IPYTHON:
                 raise GMTError(
                     "Notebook display is selected, but IPython is not available. "
                     "Make sure you have IPython installed, "