fix SparseDataFrame check

graphtools/base.py

@@ -127,23 +127,27 @@ def __init__(
         self._check_data(data)
         n_pca, rank_threshold = self._parse_n_pca_threshold(data, n_pca, rank_threshold)
         try:
+            pd
+        except NameError:
+            # pandas not installed
+            pass
+        else:
             if utils.is_SparseDataFrame(data):
                 data = data.to_coo()
             elif isinstance(data, pd.DataFrame):
                 try:
                     data = data.sparse.to_coo()
                 except AttributeError:
                     data = np.array(data)
-        except NameError:
-            # pandas not installed
-            pass
 
         try:
-            if isinstance(data, anndata.AnnData):
-                data = data.X
+            anndata
         except NameError:
             # anndata not installed
             pass
+        else:
+            if isinstance(data, anndata.AnnData):
+                data = data.X
         self.data = data
         self.n_pca = n_pca
         self.rank_threshold = rank_threshold

graphtools/utils.py

@@ -1,6 +1,13 @@
 import numpy as np
 from scipy import sparse
 import numbers
+import warnings
+
+try:
+    import pandas as pd
+except ImportError:
+    # pandas not installed
+    pass
 
 
 def if_sparse(sparse_func, dense_func, *args, **kwargs):
@@ -82,10 +89,16 @@ def to_array(X):
 
 
 def is_SparseDataFrame(X):
-    with warnings.catchwarnings():
+    try:
+        pd
+    except NameError:
+        # pandas not installed
+        return False
+    with warnings.catch_warnings():
         warnings.filterwarnings(
-            FutureWarning,
+            "ignore",
             "The SparseDataFrame class is removed from pandas. Accessing it from the top-level namespace will also be removed in the next version",
+            FutureWarning,
         )
         try:
             return isinstance(X, pd.SparseDataFrame)