class mywindow(QtWidgets.QWidget,Ui_Form): from PyQt5 import QtWidgets, QtGui

UI_1.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Form</class>
 <widget class="QWidget" name="Form">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>411</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Form</string>
  </property>
  <widget class="QPushButton" name="pushButton">
   <property name="geometry">
    <rect>
     <x>80</x>
     <y>50</y>
     <width>261</width>
     <height>31</height>
    </rect>
   </property>
   <property name="text">
    <string>PushButton</string>
   </property>
  </widget>
  <widget class="QTextEdit" name="textEdit">
   <property name="geometry">
    <rect>
     <x>80</x>
     <y>130</y>
     <width>261</width>
     <height>151</height>
    </rect>
   </property>
  </widget>
 </widget>
 <resources/>
 <connections>
  <connection>
   <sender>pushButton</sender>
   <signal>clicked()</signal>
   <receiver>textEdit</receiver>
   <slot>clear()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>210</x>
     <y>65</y>
    </hint>
    <hint type="destinationlabel">
     <x>210</x>
     <y>205</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

pyuic5 form.ui -o form.py

form.py

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'UI_1.ui'
#
# Created by: PyQt5 UI code generator 5.6
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_Form(object):
    def setupUi(self, Form):
        Form.setObjectName("Form")
        Form.resize(411, 300)
        self.pushButton = QtWidgets.QPushButton(Form)
        self.pushButton.setGeometry(QtCore.QRect(80, 50, 261, 31))
        self.pushButton.setObjectName("pushButton")
        self.textEdit = QtWidgets.QTextEdit(Form)
        self.textEdit.setGeometry(QtCore.QRect(80, 130, 261, 151))
        self.textEdit.setObjectName("textEdit")

        self.retranslateUi(Form)
        #self.pushButton.clicked.connect(self.textEdit.clear)
        self.pushButton.clicked.connect(self.hello)
        QtCore.QMetaObject.connectSlotsByName(Form)

    def retranslateUi(self, Form):
        _translate = QtCore.QCoreApplication.translate
        Form.setWindowTitle(_translate("Form", "Form"))
        self.pushButton.setText(_translate("Form", "PushButton"))

call_form.py

# -*- coding:gb2312 -*-
'''
from PyQt5 import QtWidgets, QtGui
import sys

app = QtWidgets.QApplication(sys.argv)
window = QtWidgets.QWidget();
window.show()
sys.exit(app.exec_())
'''
from PyQt5 import QtWidgets, QtGui
import sys

from form import Ui_Form    # 导入生成form.py里生成的类

class mywindow(QtWidgets.QWidget,Ui_Form):    
    def __init__(self):    
        super(mywindow,self).__init__()    
        self.setupUi(self)

    #定义槽函数
    def hello(self):
        self.textEdit.setText("hello world")

app = QtWidgets.QApplication(sys.argv)
window = mywindow()
window.show()
sys.exit(app.exec_())