""" Remove rows from a columnar file based on the values in a specified row. """
from hed.tools.remodeling.operations.base_op import BaseOp
[docs]class RemoveRowsOp(BaseOp):
""" Remove rows from a columnar file based on the values in a specified row.
Required remodeling parameters:
- **column_name** (*str*): The name of column to be tested.
- **remove_values** (*list*): The values to test for row removal.
"""
NAME = "remove_rows"
PARAMS = {
"type": "object",
"properties": {
"column_name": {
"type": "string",
"description": "Name of the key column to determine which rows to remove."
},
"remove_values": {
"type": "array",
"description": "List of key values for rows to remove.",
"items": {
"type": [
"string",
"number"
]
},
"minItems": 1,
"uniqueItems": True
}
},
"required": [
"column_name",
"remove_values"
],
"additionalProperties": False
}
[docs] def __init__(self, parameters):
""" Constructor for remove rows operation.
Parameters:
parameters (dict): Dictionary with the parameter values for required and optional parameters.
"""
super().__init__(parameters)
self.column_name = parameters["column_name"]
self.remove_values = parameters["remove_values"]
[docs] def do_op(self, dispatcher, df, name, sidecar=None):
""" Remove rows with the values indicated in the column.
Parameters:
dispatcher (Dispatcher): Manages the operation I/O.
df (DataFrame): The DataFrame to be remodeled.
name (str): Unique identifier for the dataframe -- often the original file path.
sidecar (Sidecar or file-like): Not needed for this operation.
Returns:
Dataframe: A new dataframe after processing.
"""
df_new = df.copy()
if self.column_name not in df_new.columns:
return df_new
for value in self.remove_values:
df_new = df_new.loc[df_new[self.column_name] != value, :]
return df_new