Add use-case oriented extras and helpful error messages

- Added 'analytics' extra for use-case oriented installation
- Added try/except blocks with helpful error messages for missing dependencies:
  - NumPy: suggests installing [analytics] or [all]
  - Pandas: suggests installing [dataframe] or [all]
- Updated README to highlight analytics extra instead of numpy
- Error messages guide users to install correct extras
- All 55 tests pass

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>

Author: Copilot

README.md

@@ -20,7 +20,7 @@ If you only need `PrometheusConnect` without DataFrame support or plotting capab
 
 To install only specific extras:
 - For DataFrame support: `pip install prometheus-api-client[dataframe]`
-- For numpy support: `pip install prometheus-api-client[numpy]`
+- For analytics/aggregation operations: `pip install prometheus-api-client[analytics]`
 - For plotting support: `pip install prometheus-api-client[plot]`
 
 To install directly from this branch:

prometheus_api_client/metric.py

@@ -1,7 +1,15 @@
 """A Class for metric object."""
 from copy import deepcopy
 import datetime
-import pandas
+
+try:
+    import pandas
+except ImportError as e:
+    raise ImportError(
+        "Pandas is required for Metric class. "
+        "Please install it with: pip install prometheus-api-client[dataframe] "
+        "or pip install prometheus-api-client[all]"
+    ) from e
 
 from prometheus_api_client.exceptions import MetricValueConversionError
 

prometheus_api_client/metric_range_df.py

@@ -1,6 +1,14 @@
 """A pandas.DataFrame subclass for Prometheus range vector responses."""
-from pandas import DataFrame, to_datetime
-from pandas._typing import Axes, Dtype
+try:
+    from pandas import DataFrame, to_datetime
+    from pandas._typing import Axes, Dtype
+except ImportError as e:
+    raise ImportError(
+        "Pandas is required for MetricRangeDataFrame class. "
+        "Please install it with: pip install prometheus-api-client[dataframe] "
+        "or pip install prometheus-api-client[all]"
+    ) from e
+
 from typing import Optional, Sequence
 
 from prometheus_api_client.exceptions import MetricValueConversionError

prometheus_api_client/metric_snapshot_df.py

@@ -1,6 +1,14 @@
 """A pandas.DataFrame subclass for Prometheus query response."""
-from pandas import DataFrame, to_datetime
-from pandas._typing import Axes, Dtype
+try:
+    from pandas import DataFrame, to_datetime
+    from pandas._typing import Axes, Dtype
+except ImportError as e:
+    raise ImportError(
+        "Pandas is required for MetricSnapshotDataFrame class. "
+        "Please install it with: pip install prometheus-api-client[dataframe] "
+        "or pip install prometheus-api-client[all]"
+    ) from e
+
 from typing import Optional, Sequence
 
 from prometheus_api_client.exceptions import MetricValueConversionError

prometheus_api_client/prometheus_connect.py

@@ -568,7 +568,14 @@ def get_metric_aggregation(
                 'max': 6.009373
              }
         """
-        import numpy
+        try:
+            import numpy
+        except ImportError as e:
+            raise ImportError(
+                "NumPy is required for metric aggregation operations. "
+                "Please install it with: pip install prometheus-api-client[analytics] "
+                "or pip install prometheus-api-client[all]"
+            ) from e
 
         if not isinstance(operations, list):
             raise TypeError("Operations can be only of type list")

setup.py

@@ -40,6 +40,7 @@ def get_version():
         "dataframe": ["pandas>=1.4.0"],
         "numpy": ["numpy"],
         "plot": ["matplotlib"],
+        "analytics": ["numpy"],
         "all": ["pandas>=1.4.0", "numpy", "matplotlib"],
     },
     packages=setuptools.find_packages(),