Made it work and test on 3.5 again

.travis.yml

@@ -1,6 +1,6 @@
 language: python
 python:
-  #- "3.5"  # loompy needs python 3.6
+  - "3.5"
   - "3.6"
 install:
   - "pip install -r requires.txt"

anndata/base.py

@@ -284,7 +284,7 @@ def __repr__(self):
         if self._filename is None:
             return 'Backing file manager: no file is set.'
         else:
-            return f'Backing file manager of file {self._filename}.'
+            return 'Backing file manager of file {}.'.format(self._filename)
 
     def __getitem__(self, key):
         return self._file[key]
@@ -523,9 +523,9 @@ def __init__(self, n_dims):
 
 
 class AnnData(IndexMixin, metaclass=utils.DeprecationMixinMeta):
-    __doc__ = dedent(f"""An annotated data matrix.
+    __doc__ = dedent("""An annotated data matrix.
 
-    {indent(_MAIN_NARRATIVE, 4*' ')}
+    {}
 
     Parameters
     ----------
@@ -583,7 +583,7 @@ class AnnData(IndexMixin, metaclass=utils.DeprecationMixinMeta):
 
     .. _statsmodels: http://www.statsmodels.org/stable/index.html
     .. _scikit-learn: http://scikit-learn.org/
-    """)
+    """).format(indent(_MAIN_NARRATIVE, 4*' '))
 
     _BACKED_ATTRS = ['X', 'raw.X']
 

anndata/h5py/h5sparse.py

@@ -98,7 +98,7 @@ def __init__(
         libver: Optional[str] = None,
         userblock_size: Optional[int] = None,
         swmr: bool = False,
-        **kwds,
+        **kwds  # Python 3.5 can’t handle trailing commas here
     ):
         self.h5f = h5py.File(
             name,

anndata/readwrite/write.py

@@ -45,7 +45,7 @@ def write_csvs(dirname: Union[Path, str], adata: AnnData, skip_data: bool = True
         filename = dirname
         if key not in {'X', 'var', 'obs', 'obsm', 'varm'}:
             filename = dir_uns
-        filename /= f'{key}.csv'
+        filename /= '{}.csv'.format(key)
         df = value
         if not isinstance(value, pd.DataFrame):
             value = np.array(value)
@@ -54,7 +54,7 @@ def write_csvs(dirname: Union[Path, str], adata: AnnData, skip_data: bool = True
             try:
                 df = pd.DataFrame(value)
             except Exception as e:
-                warnings.warn(f'Omitting to write {key!r}.', type(e))
+                warnings.warn('Omitting to write {!r}.'.format(key), type(e))
                 continue
         df.to_csv(
             filename, sep=sep,

anndata/tests/readwrite.py

@@ -1,13 +1,16 @@
+from importlib.util import find_spec
 from pathlib import Path
 
 import numpy as np
 import pandas as pd
+import pytest
 from scipy.sparse import csr_matrix
 import anndata as ad
 
 
 HERE = Path(__file__).parent
 
+
 # -------------------------------------------------------------------------------
 # Some test data
 # -------------------------------------------------------------------------------
@@ -61,6 +64,7 @@ def test_readwrite_dynamic():
         assert adata.obs['oanno1'].cat.categories.tolist() == ['cat1', 'cat2']
 
 
+@pytest.mark.skipif(not find_spec('loompy'), reason='Loompy is not installed (expected on Python 3.5)')
 def test_readwrite_loom():
     for i, typ in enumerate([np.array, csr_matrix]):
         X = typ(X_list)

anndata/utils.py

@@ -92,8 +92,8 @@ def decorator(func):
         def new_func(*args, **kwargs):
             warnings.simplefilter('always', DeprecationWarning)  # turn off filter
             warnings.warn(
-                f'Use {new_name} instead of {func.__name__}, '
-                f'{func.__name__} will be removed in the future.',
+                'Use {0} instead of {1}, {1} will be removed in the future.'
+                .format(new_name, func.__name__),
                 category=DeprecationWarning,
                 stacklevel=2,
             )

requires_tests.txt

@@ -1 +1 @@
-loompy>=2.0
+loompy>=2.0; python_version>='3.6'