Files
quantconnect--lean/Common/Exceptions/NoMethodMatchPythonExceptionInterpreter.cs
2026-07-13 13:02:50 +08:00

108 lines
4.6 KiB
C#

/*
* QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
* Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using Python.Runtime;
using QuantConnect.Util;
namespace QuantConnect.Exceptions
{
/// <summary>
/// Interprets <see cref="NoMethodMatchPythonExceptionInterpreter"/> instances
/// </summary>
public class NoMethodMatchPythonExceptionInterpreter : PythonExceptionInterpreter
{
/// <summary>
/// Determines the order that an instance of this class should be called
/// </summary>
public override int Order => 0;
/// <summary>
/// Determines if this interpreter should be applied to the specified exception.
/// </summary>
/// <param name="exception">The exception to check</param>
/// <returns>True if the exception can be interpreted, false otherwise</returns>
public override bool CanInterpret(Exception exception)
{
return base.CanInterpret(exception) &&
exception.Message.Contains(Messages.NoMethodMatchPythonExceptionInterpreter.NoMethodMatchExpectedSubstring);
}
/// <summary>
/// Interprets the specified exception into a new exception
/// </summary>
/// <param name="exception">The exception to be interpreted</param>
/// <param name="innerInterpreter">An interpreter that should be applied to the inner exception.</param>
/// <returns>The interpreted exception</returns>
public override Exception Interpret(Exception exception, IExceptionInterpreter innerInterpreter)
{
var pe = (PythonException)exception;
var methodName = GetMethodName(pe.Message);
var message = Messages.NoMethodMatchPythonExceptionInterpreter.AttemptedToAccessMethodThatDoesNotExist(methodName);
var overloadsHint = GetOverloadsHint(pe.Message);
if (!string.IsNullOrEmpty(overloadsHint))
{
message += $" {overloadsHint}";
}
message += PythonUtil.PythonExceptionStackParser(pe.StackTrace);
return new MissingMethodException(message, pe);
}
/// <summary>
/// Extracts the name of the method that failed to resolve from the Python exception message.
/// The message has the form: "No method matches given arguments for {methodName}: ({argumentTypes})",
/// so the method name sits between the "for " keyword and the following ":".
/// </summary>
private static string GetMethodName(string exceptionMessage)
{
const string forKeyword = "for ";
var forIndex = exceptionMessage.IndexOfInvariant(forKeyword);
if (forIndex == -1)
{
// Unexpected format, fall back to the whole message
return exceptionMessage.Trim();
}
var methodNameStart = forIndex + forKeyword.Length;
var colonIndex = exceptionMessage.IndexOf(':', methodNameStart);
var methodName = colonIndex > methodNameStart
? exceptionMessage.Substring(methodNameStart, colonIndex - methodNameStart)
: exceptionMessage.Substring(methodNameStart);
return methodName.Trim();
}
/// <summary>
/// Extracts the candidate-signatures hint pythonnet appends to the binding-failure
/// message ("The expected signature is:" or "The following overloads are available:"
/// followed by the signatures), so the interpreted message can keep it.
/// </summary>
private static string GetOverloadsHint(string exceptionMessage)
{
var hintIndex = exceptionMessage.IndexOfInvariant("The expected signature is:");
if (hintIndex == -1)
{
hintIndex = exceptionMessage.IndexOfInvariant("The following overloads are available:");
}
return hintIndex == -1 ? null : exceptionMessage.Substring(hintIndex).Trim();
}
}
}