1/4 mile calculator written in PyQt5 in Python

1/4 mile straight line acceleration is a common metric used to evaluate the performance of cars and motorcycles. Enthusiasts and experts alike use this distance to evaluate acceleration and overall ability. In this article, we will build a basic 1/4 mile estimator using PyQt5, a well-known Python library for creating graphical user interfaces (GUIs). By the end of this article, you will have a fully functional 1/4 mile estimator that you can use to evaluate the performance of a variety of vehicles.

Why choose PyQt5 as the 1/4 mile estimator?

PyQt5 is a powerful and versatile library for building desktop applications in Python. It provides an intuitive set of tools for generating high-level, user-friendly GUIs that run on multiple platforms, including Windows, macOS, and Linux. Due to its user-friendliness, cross-platform compatibility and extensive documentation, PyQt5 is particularly suitable for developing quarter mile estimators.

Stages of building a 1/4 mile estimator in Python using PyQt5

Install PyQt5

Before we begin, we must install PyQt5. You can do this using pip (Python package installer), just execute the following command -

pip install PyQt5

Integrate necessary modules

First, let’s combine the basic PyQt5 module with Python’s built-in math module.

import sys import math from PyQt5.QtWidgets import QApplication, QWidget, QVBoxLayout, QLabel, QLineEdit, QPushButton

Developing main application classes

Subsequently, create a main application window class that inherits from QWidget. This class will contain the components and layout of our estimator.

class QuarterMileEstimator(QWidget): def init(self): super().init()

   # 初始化UI元素
   self.init_ui()

def init_ui(self):
   # 创建和配置UI元素
   layout = QVBoxLayout()

   self.title = QLabel('1/4 Mile Estimator')
   self.weight_label = QLabel('Weight (lbs):')
   self.weight_input = QLineEdit()
   self.hp_label = QLabel('Horsepower:')
   self.hp_input = QLineEdit()
   self.calculate_button = QPushButton('Estimate')
   self.result_label = QLabel('')

   # 将UI元素添加到布局中
   layout.addWidget(self.title)
   layout.addWidget(self.weight_label)
   layout.addWidget(self.weight_input)
   layout.addWidget(self.hp_label)
   layout.addWidget(self.hp_input)
   layout.addWidget(self.calculate_button)
   layout.addWidget(self.result_label)

   # 将估计按钮连接到计算函数
   self.calculate_button.clicked.connect(self.estimate_quarter_mile)

   # 设置小部件的布局
   self.setLayout(layout)

time (seconds) = 6.269 * sqrt(weight (lbs) / horsepower)
def estimate_quarter_mile(self):
   try:
      weight = float(self.weight_input.text())
      horsepower = float(self.hp_input.text())

      # 计算1/4英里时间
      time = 6.269 * math.sqrt(weight / horsepower)

      # 显示结果
      self.result_label.setText(f'Approximated 1/4 Mile Time: {time:.2f} seconds')
   except ValueError:
      # 如果输入无效，则显示错误消息
      self.result_label.setText('Error: Invalid input. Please enter valid numbers for weight and horsepower.')

if name == 'main': app = QApplication(sys.argv) estimator = QuarterMileEstimator()

estimator.setWindowTitle('1/4 Mile Estimator')
estimator.show()

sys.exit(app().exec_())

• Define a QuarterMileEstimator class that inherits from QWidget. Define the init method to initialize the object and call the init_ui method.

• In the init_ui method, generate and configure UI elements such as labels, input fields, and buttons. Add UI elements to the QVBoxLayout layout.

• Connect the estimated button's click signal to the estimate_quarter_mile method, which we will define in the next stage. Sets the layout of the QuarterMileEstimator widget.

Achieve 1/4 Mile Estimate

Now, let's incorporate the estimation logic into our estimator. We will use the following formula to approximate 1/4 mile time -

时间（秒）= 6.269 * sqrt(重量（磅）/ 马力)

Create estimate_quarter_mile method in QuarterMileEstimator class to perform this estimation -

def estimate_quarter_mile(self):
   try:
      weight = float(self.weight_input.text())
      horsepower = float(self.hp_input.text())

      # 计算1/4英里时间
      time = 6.269 * math.sqrt(weight / horsepower)

      # 显示结果
      self.result_label.setText(f'Approximated 1/4 Mile Time: {time:.2f} seconds')
   except ValueError:
      # 如果输入无效，则显示错误消息
      self.result_label.setText('Error: Invalid input. Please enter valid numbers for weight and horsepower.')

• Define the estimate_quarter_mile method in the QuarterMileEstimator class.

• Get the weight and horsepower values ​​from the input fields and convert them to floating point numbers. Use the formula to calculate your estimated 1/4 mile time.

• Display the result in result_label QLabel. If a ValueError occurs (for example, if the input field contains a non-numeric value), an error message is displayed.

Set up the main application loop

Finally, create the main application loop to operate the estimator −

最终，创建主应用程序循环来操作估算器：

if name == 'main': app = QApplication(sys.argv) estimator = QuarterMileEstimator()

estimator.setWindowTitle('1/4 Mile Estimator')
estimator.show()

sys.exit(app().exec_())

• Verify that the script is executed as the main program (i.e. not imported as a module). Create a QApplication object and pass in command line parameters.

• Create an instance of the QuarterMileEstimator class. Set the window title and display the estimator using the show method.

• Use app.exec_() to run the application's event loop and exit the script when the loop ends.

Output

---------------------------
| 1/4英里估计器           |
---------------------------
| 重量（磅）：            |
| [_______________]       |
| 马力：                  |
| [_______________]       |
| [估计]                  |
|                         |
| 大约1/4英里时间： ____ 秒 |
---------------------------

in conclusion

By following these stages, you now have a fully functional 1/4 mile estimator, using PyQt5 in Python. This simple yet powerful tool evaluates the performance of various vehicles based on their weight and horsepower. Using PyQt5, you can easily create cross-platform desktop applications suitable for a variety of use cases, from basic estimators to complex productivity tools.

As you continue to improve your Python and PyQt5 skills, consider exploring more complex features and techniques, such as integrating with databases, incorporating multimedia, and making custom widgets. Through continuous learning and experimentation, you'll be able to tackle any desktop application project.

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