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Marchma0Monta120
Marchma0
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Enh/motor thrustcurve api (#870)
* Add the function to create a motor from the API of thrustcurve and the test * Improve load_from_thrustcurve_api and test_load_from_thrustcurve_api with clean imports * Clean up load_from_thrustcurve_api and improve test_load_from_thrustcurve_api with exception testing * Use warnings.warn() in load_from_thrustcurve_api when motor is found (as requested) * Added documentation for the load_from_thrustcurve_api method into the genericmotors.rst file * Changes to conform to lint * Fixed Pylint errors * Update docs/user/motors/genericmotor.rst Co-authored-by: Gui-FernandesBR <63590233+Gui-FernandesBR@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Gui-FernandesBR <63590233+Gui-FernandesBR@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Set private the method call_thrustcurve_api * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update tests/unit/motors/test_genericmotor.py Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update rocketpy/motors/motor.py Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Modify the changelog * Bug fix * Refactor GenericMotor class: comment out unused designation and manufacturer variables * Add the function to create a motor from the API of thrustcurve and the test * Improve load_from_thrustcurve_api and test_load_from_thrustcurve_api with clean imports * Clean up load_from_thrustcurve_api and improve test_load_from_thrustcurve_api with exception testing * Use warnings.warn() in load_from_thrustcurve_api when motor is found (as requested) * Added documentation for the load_from_thrustcurve_api method into the genericmotors.rst file * Changes to conform to lint * Fixed Pylint errors * Update docs/user/motors/genericmotor.rst Co-authored-by: Gui-FernandesBR <63590233+Gui-FernandesBR@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Gui-FernandesBR <63590233+Gui-FernandesBR@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Set private the method call_thrustcurve_api * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update tests/unit/motors/test_genericmotor.py Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update rocketpy/motors/motor.py Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update docs/user/motors/genericmotor.rst Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Modify the changelog * Bug fix --------- Co-authored-by: monta <montadharettaieb@gmail.com>
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‎CHANGELOG.md‎

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@@ -32,6 +32,7 @@ Attention: The newest changes should be on top -->
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### Added
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- ENH: Add thrustcurve api integration to retrieve motor eng data [#870](https://github.com/RocketPy-Team/RocketPy/pull/870)
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- ENH: Custom Exception errors and messages [#285](https://github.com/RocketPy-Team/RocketPy/issues/285)
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### Changed

‎docs/user/motors/genericmotor.rst‎

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@@ -106,3 +106,30 @@ note that the user can still provide the parameters manually if needed.
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The ``load_from_eng_file`` method is a very useful tool for simulating motors \
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when the user does not have all the information required to build a ``SolidMotor`` yet.
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The ``load_from_thrustcurve_api`` method
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----------------------------------------
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The ``GenericMotor`` class provides a convenience loader that downloads a temporary
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`.eng` file from the ThrustCurve.org public API and builds a ``GenericMotor``
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instance from it. This is useful when you know a motor designation (for example
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``"M1670"``) but do not want to manually download and
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save the `.eng` file.
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.. note::
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This method performs network requests to the ThrustCurve API. Use it only
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when you have network access. For automated testing or reproducible runs,
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prefer using local `.eng` files.
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Example
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-------
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.. jupyter-execute::
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from rocketpy.motors import GenericMotor
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# Build a motor by name (requires network access)
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motor = GenericMotor.load_from_thrustcurve_api("M1670")
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# Use the motor as usual
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motor.info()

‎rocketpy/motors/motor.py‎

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import base64
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import re
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import tempfile
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import warnings
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import xml.etree.ElementTree as ET
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from abc import ABC, abstractmethod
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from functools import cached_property
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from os import path
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from os import path, remove
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import numpy as np
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import requests
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from ..mathutils.function import Function, funcify_method
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from ..plots.motor_plots import _MotorPlots
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coordinate_system_orientation=coordinate_system_orientation,
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)
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@staticmethod
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def _call_thrustcurve_api(name: str):
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"""
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Download a .eng file from the ThrustCurve API
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based on the given motor name.
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Parameters
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----------
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name : str
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The motor name according to the API (e.g., "Cesaroni_M1670" or "M1670").
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Both manufacturer-prefixed and shorthand names are commonly used; if multiple
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motors match the search, the first result is used.
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Returns
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-------
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data_base64 : str
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The .eng file of the motor in base64
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Raises
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------
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ValueError
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If no motor is found or if the downloaded .eng data is missing.
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requests.exceptions.RequestException
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If a network or HTTP error occurs during the API call.
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"""
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base_url = "https://www.thrustcurve.org/api/v1"
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# Step 1. Search motor
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response = requests.get(f"{base_url}/search.json", params={"commonName": name})
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response.raise_for_status()
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data = response.json()
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if not data.get("results"):
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raise ValueError(
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f"No motor found for name '{name}'. "
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"Please verify the motor name format (e.g., 'Cesaroni_M1670' or 'M1670') and try again."
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)
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motor_info = data["results"][0]
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motor_id = motor_info.get("motorId")
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# NOTE: commented bc we don't use it, but keeping for possible future use
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# designation = motor_info.get("designation", "").replace("/", "-")
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# manufacturer = motor_info.get("manufacturer", "")
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# Step 2. Download the .eng file
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dl_response = requests.get(
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f"{base_url}/download.json",
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params={"motorIds": motor_id, "format": "RASP", "data": "file"},
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)
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dl_response.raise_for_status()
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dl_data = dl_response.json()
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if not dl_data.get("results"):
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raise ValueError(
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f"No .eng file found for motor '{name}' in the ThrustCurve API."
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)
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data_base64 = dl_data["results"][0].get("data")
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if not data_base64:
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raise ValueError(
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f"Downloaded .eng data for motor '{name}' is empty or invalid."
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)
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return data_base64
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@staticmethod
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def load_from_thrustcurve_api(name: str, **kwargs):
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"""
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Creates a Motor instance by downloading a .eng file from the ThrustCurve API
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based on the given motor name.
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Parameters
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----------
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name : str
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The motor name according to the API (e.g., "Cesaroni_M1670" or "M1670").
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Both manufacturer-prefixed and shorthand names are commonly used; if multiple
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motors match the search, the first result is used.
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**kwargs :
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Additional arguments passed to the Motor constructor or loader, such as
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dry_mass, nozzle_radius, etc.
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Returns
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-------
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instance : GenericMotor
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A new GenericMotor instance initialized using the downloaded .eng file.
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Raises
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------
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ValueError
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If no motor is found or if the downloaded .eng data is missing.
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requests.exceptions.RequestException
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If a network or HTTP error occurs during the API call.
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"""
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data_base64 = GenericMotor._call_thrustcurve_api(name)
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data_bytes = base64.b64decode(data_base64)
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# Step 3. Create the motor from the .eng file
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tmp_path = None
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try:
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# create a temporary file that persists until we explicitly remove it
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with tempfile.NamedTemporaryFile(suffix=".eng", delete=False) as tmp_file:
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tmp_file.write(data_bytes)
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tmp_file.flush()
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tmp_path = tmp_file.name
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return GenericMotor.load_from_eng_file(tmp_path, **kwargs)
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finally:
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# Ensuring the temporary file is removed
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if tmp_path and path.exists(tmp_path):
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try:
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remove(tmp_path)
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except OSError:
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# If cleanup fails, don't raise: we don't want to mask prior exceptions.
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pass
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def all_info(self):
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"""Prints out all data and graphs available about the Motor."""
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# Print motor details

‎tests/unit/motors/test_genericmotor.py‎

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import base64
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import numpy as np
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import pytest
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import requests
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import scipy.integrate
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from rocketpy import Function, Motor
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assert thrust_curve[0][1] == 0.0 # First thrust point
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assert thrust_curve[-1][0] == 2.2 # Last point of time
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assert thrust_curve[-1][1] == 0.0 # Last thrust point
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class MockResponse:
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"""Mocked response for requests."""
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def __init__(self, json_data):
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self._json_data = json_data
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def json(self):
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return self._json_data
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def raise_for_status(self):
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return None
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def _mock_get(search_results=None, download_results=None):
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"""Return a mock_get function with predefined search/download results."""
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def _get(url, **_kwargs):
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if "search.json" in url:
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return MockResponse(search_results or {"results": []})
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if "download.json" in url:
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return MockResponse(download_results or {"results": []})
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raise RuntimeError(f"Unexpected URL: {url}")
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return _get
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# Module-level constant for expected motor specs
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EXPECTED_MOTOR_SPECS = {
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"burn_time": (0, 3.9),
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"dry_mass": 2.130,
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"propellant_initial_mass": 3.101,
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"chamber_radius": 75 / 1000,
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"chamber_height": 757 / 1000,
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"nozzle_radius": (75 / 1000) * 0.85,
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"average_thrust": 1545.218,
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"total_impulse": 6026.350,
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"max_thrust": 2200.0,
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"exhaust_velocity": 1943.357,
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"chamber_position": 0,
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}
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def assert_motor_specs(motor):
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specs = EXPECTED_MOTOR_SPECS
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assert motor.burn_time == specs["burn_time"]
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assert motor.dry_mass == specs["dry_mass"]
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assert motor.propellant_initial_mass == specs["propellant_initial_mass"]
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assert motor.chamber_radius == specs["chamber_radius"]
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assert motor.chamber_height == specs["chamber_height"]
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assert motor.chamber_position == specs["chamber_position"]
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assert motor.average_thrust == pytest.approx(specs["average_thrust"])
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assert motor.total_impulse == pytest.approx(specs["total_impulse"])
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assert motor.exhaust_velocity.average(*specs["burn_time"]) == pytest.approx(
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specs["exhaust_velocity"]
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)
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assert motor.max_thrust == pytest.approx(specs["max_thrust"])
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assert motor.nozzle_radius == pytest.approx(specs["nozzle_radius"])
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def test_load_from_thrustcurve_api(monkeypatch, generic_motor):
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"""Tests GenericMotor.load_from_thrustcurve_api with mocked API."""
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eng_path = "data/motors/cesaroni/Cesaroni_M1670.eng"
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with open(eng_path, "rb") as f:
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encoded = base64.b64encode(f.read()).decode("utf-8")
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search_json = {
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"results": [
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{
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"motorId": "12345",
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"designation": "Cesaroni_M1670",
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"manufacturer": "Cesaroni",
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}
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]
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}
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download_json = {"results": [{"data": encoded}]}
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monkeypatch.setattr(requests, "get", _mock_get(search_json, download_json))
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monkeypatch.setattr(requests.Session, "get", _mock_get(search_json, download_json))
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motor = type(generic_motor).load_from_thrustcurve_api("M1670")
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assert_motor_specs(motor)
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_, _, points = Motor.import_eng(eng_path)
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assert motor.thrust.y_array == pytest.approx(
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Function(points, "Time (s)", "Thrust (N)", "linear", "zero").y_array
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)
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error_cases = [
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("No motor found", {"results": []}, None),
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(
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"No .eng file found",
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{
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"results": [
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{"motorId": "123", "designation": "Fake", "manufacturer": "Test"}
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]
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},
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{"results": []},
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),
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(
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"Downloaded .eng data",
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{
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"results": [
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{"motorId": "123", "designation": "Fake", "manufacturer": "Test"}
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]
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},
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{"results": [{"data": ""}]},
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),
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]
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for msg, search_res, download_res in error_cases:
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monkeypatch.setattr(requests, "get", _mock_get(search_res, download_res))
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monkeypatch.setattr(
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requests.Session, "get", _mock_get(search_res, download_res)
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)
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with pytest.raises(ValueError, match=msg):
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type(generic_motor).load_from_thrustcurve_api("FakeMotor")

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