Add pandera as a core dependency

recommenders/datasets/movielens.py

@@ -7,6 +7,9 @@
 import shutil
 import warnings
 import pandas as pd
+import pandera as pa
+from pandera import Field
+from pandera.typing import Series
 from typing import Optional
 from zipfile import ZipFile
 from recommenders.datasets.download_utils import maybe_download, download_path
@@ -21,6 +24,7 @@
     DEFAULT_GENRE_COL,
 )
 
+
 try:
     from pyspark.sql.types import (
         StructType,
@@ -34,13 +38,6 @@
 except ImportError:
     pass  # so the environment without spark doesn't break
 
-try:
-    import pandera as pa
-    from pandera import Field
-    from pandera.typing import Series
-except ImportError:
-    pass  # so the environment without recommender['dev'] doesn't break
-
 
 class _DataFormat:
     def __init__(

setup.py

@@ -45,6 +45,7 @@
     "cornac>=1.1.2,<2",
     "scikit-surprise>=0.19.1,<=1.1.1",
     "retrying>=1.3.3",
+    "pandera[strategies]>=0.6.5",  # For generating fake datasets
 ]
 
 # shared dependencies
@@ -75,7 +76,6 @@
     ],
     "dev": [
         "black>=18.6b4,<21",
-        "pandera[strategies]>=0.6.5",  # For generating fake datasets
         "pytest>=3.6.4",
         "pytest-cov>=2.12.1",
         "pytest-mock>=3.6.1",  # for access to mock fixtures in pytest