Table.view_as() performance fixes

src/lgdo/logging.py

@@ -16,7 +16,7 @@
 def setup(level: int = logging.INFO, logger: logging.Logger | None = None) -> None:
     """Setup a colorful logging output.
 
-    If `logger` is None, sets up only the ``pygama`` logger.
+    If `logger` is None, sets up only the ``lgdo`` logger.
 
     Parameters
     ----------
@@ -27,7 +27,7 @@ def setup(level: int = logging.INFO, logger: logging.Logger | None = None) -> No
 
     Examples
     --------
-    >>> from pygama import logging
+    >>> from lgdo import logging
     >>> logging.setup(level=logging.DEBUG)
     """
     handler = colorlog.StreamHandler()
@@ -36,7 +36,7 @@ def setup(level: int = logging.INFO, logger: logging.Logger | None = None) -> No
     )
 
     if logger is None:
-        logger = colorlog.getLogger("pygama")
+        logger = colorlog.getLogger("lgdo")
 
     logger.setLevel(level)
     logger.addHandler(handler)

src/lgdo/types/array.py

@@ -182,6 +182,7 @@ def view_as(
             if self.nda.ndim == 1:
                 return pd.Series(self.nda, copy=False)
 
+            # if array is multi-dim, use awkward
             return akpd.from_awkward(self.view_as("ak"))
 
         if library == "np":
@@ -195,6 +196,7 @@ def view_as(
                 msg = "Pint does not support Awkward yet, you must view the data with_units=False"
                 raise ValueError(msg)
 
+            # NOTE: this is zero-copy!
             return ak.Array(self.nda)
 
         msg = f"{library} is not a supported third-party format."

src/lgdo/types/table.py

@@ -381,49 +381,55 @@ def view_as(
             forward physical units to the output data.
         cols
             a list of column names specifying the subset of the table's columns
-            to be added to the dataframe.
+            to be added to the data view structure.
         prefix
-            The prefix to be added to the column names. Used when recursively getting the
-            dataframe of a table inside this table.
+            The prefix to be added to the column names. Used when recursively
+            getting the dataframe of a :class:`Table` inside this
+            :class:`Table`.
 
         See Also
         --------
         .LGDO.view_as
         """
+        if cols is None:
+            cols = self.keys()
+
         if library == "pd":
             df = pd.DataFrame()
-            if cols is None:
-                cols = self.keys()
+
             for col in cols:
-                column = self[col]
-                if isinstance(column, (Array, VectorOfVectors)):
-                    tmp_ser = column.view_as("pd", with_units=with_units).rename(
-                        prefix + str(col)
-                    )
-                    df = pd.DataFrame(tmp_ser) if df.empty else df.join(tmp_ser)
-                elif isinstance(column, Table):
-                    tmp_df = column.view_as(
+                data = self[col]
+
+                if isinstance(data, Table):
+                    log.debug(f"viewing Table {col=!r} recursively")
+
+                    tmp_df = data.view_as(
                         "pd", with_units=with_units, prefix=f"{prefix}{col}_"
                     )
-                    df = tmp_df if df.empty else df.join(tmp_df)
-                elif df.empty:
-                    df[prefix + str(col)] = column.view_as("pd", with_units=with_units)
+                    for k, v in tmp_df.items():
+                        df[k] = v
+
                 else:
-                    df[prefix + str(col)] = df.join(
-                        column.view_as("pd", with_units=with_units)
+                    log.debug(
+                        f"viewing {type(data).__name__} column {col!r} as Pandas Series"
                     )
+                    df[f"{prefix}{col}"] = data.view_as("pd", with_units=with_units)
+
             return df
 
         if library == "np":
-            msg = f"Format {library} is not supported for Tables."
+            msg = f"Format {library!r} is not supported for Tables."
             raise TypeError(msg)
 
         if library == "ak":
             if with_units:
                 msg = "Pint does not support Awkward yet, you must view the data with_units=False"
                 raise ValueError(msg)
 
-            return ak.Array(self)
+            # NOTE: passing the Table directly (which inherits from a dict)
+            # makes it somehow really slow. Not sure why, but this could be due
+            # to extra LGDO fields (like "attrs")
+            return ak.Array({col: self[col].view_as("ak") for col in cols})
 
-        msg = f"{library} is not a supported third-party format."
+        msg = f"{library!r} is not a supported third-party format."
         raise TypeError(msg)