用python生成能显示wav文件的波形，还可以在时间轴上进行裁剪截取部分波形并保存波形文件的PYQT程序

下面是一个简单的PYQT程序，它可以用于显示WAV文件的波形，并允许用户在时间轴上裁剪和保存部分波形：

import sys
import wave
import numpy as np
from PyQt5.QtWidgets import QApplication, QMainWindow, QAction, QFileDialog
from PyQt5.QtGui import QIcon, QPainter

class WaveformWidget(QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setMinimumSize(400, 200)
        self._data = None
        self._pos = None

    def set_data(self, data, pos):
        self._data = data
        self._pos = pos
        self.update()

    def paintEvent(self, event):
        if self._data is None:
            return
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.setPen(Qt.blue)
        width, height = self.width(), self.height()
        x_scale = width / len(self._data)
        y_scale = height / 2**15
        path = QPainterPath()
        path.moveTo(0, height / 2)
        for i in range(len(self._data)):
            x = i * x_scale
            y = self._data[i] * y_scale + height / 2
            path.lineTo(x, y)
        painter.drawPath(path)
        if self._pos is not None:
            painter.setPen(Qt.red)
            x = self._pos * x_scale
            painter.drawLine(x, 0, x, height)

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('Waveform Viewer')
        self.setCentralWidget(WaveformWidget())
        self.create_actions()
        self.create_menus()

    def create_actions(self):
        self.open_action = QAction(QIcon('open.png'), 'Open', self)
        self.open_action.setShortcut('Ctrl+O')
        self.open_action.triggered.connect(self.open_file)
        self.save_action = QAction(QIcon('save.png'), 'Save', self)
        self.save_action.setShortcut('Ctrl+S')
        self.save_action.triggered.connect(self.save_file)
        self.quit_action = QAction('Quit', self)
        self.quit_action.setShortcut('Ctrl+Q')
        self.quit_action.triggered.connect(self.close)

    def create_menus(self):
        self.file_menu = self.menuBar().addMenu('File')
        self.file_menu.addAction(self.open_action)
        self.file_menu.addAction(self.save_action)
        self.file_menu.addSeparator()
        self.file_menu.addAction(self.quit_action)

    def open_file(self):
        filename, _ = QFileDialog.getOpenFileName(self, 'Open WAV file', '', 'WAV files (*.wav)')
        if filename:
            with wave.open(filename, 'rb') as f:
                nframes = f.getnframes()
                data = np.frombuffer(f.readframes(nframes), dtype=np.int16)
            self.centralWidget().set_data(data, None)

    def save_file(self):
        filename, _ = QFileDialog.getSaveFileName(self, 'Save WAV file', '', 'WAV files (*.wav)')
        if filename:
            pos = self.centralWidget()._pos
            if pos is None:
                return
            with wave.open(filename, 'wb') as f:
                f.setnchannels(1)
                f.setsampwidth(2)
                f.setframerate(44100)
                start = int(pos * 44100)
                end = int(len(self.centralWidget()._data) * pos)
                f.writeframes(self.centralWidget()._data[start:end].tobytes())

    def mousePressEvent(self, event):
        width = self.centralWidget().width()
        pos = event.x() / width
        self.centralWidget()._pos = pos
        self.centralWidget().update()

if __name__ == '__main__':
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

注意：这个程序需要PyQt5和numpy库才能运行。在程序中，我们创建了一个名为WaveformWidget的QWidget子类，它用于显示WAV文件的波形。该类有一个名为set_data的方法，它接受一个numpy数组和一个浮点数，用于设置要显示的数据和当前位置。paintEvent方法用于绘制波形，mousePressEvent方法用于响应鼠标单击事件，并将当前位置设置为鼠标位置。MainWindow类用于创建应用程序的主窗口，并包含一个WaveformWidget实例。在这个类中，我们还创建了一些QAction和QMenu对象，用于打开和保存WAV文件。在open_file和save_file方法中，我们使用wave库来读取和写入WAV文件，使用numpy库来处理波形数据。