使用 PyQt5 的线性搜索可视化工具
在本文中，我们将看到如何制作一个 PyQt5 应用程序，它将可视化线性搜索算法。
线性搜索或顺序搜索是一种在列表中查找元素的方法。它依次检查列表的每个元素，直到找到匹配项或搜索了整个列表。 
Gui implementation steps :
1. Create a list of label according to the given list of numbers
2. Set their text, border, color and geometry with the respective gap from each other
3. Each label height should be proportional to the value of each number
4. Create a start and pause push button to start the searching and pause the searching
5. Create a result label to show the searching status
Back end implementation steps :
1. Create label list corresponding to the given numbers
2. Create a variable to count the index and flag for searching
3. Add action to the push button their action should change the flag status i.e start action should make flag true and pause action should make flag false
4. Create a timer object which calls a method after every specific time
5. Inside the timer method check for the flag is flag is true begin the linear search algorithm
6. If label value if not equal make its color grey then check for next, if value got found make label color green and stop the search and show the output in the result label.
7. If the index counter becomes equal to the list length stop the search and show result as not found.
下面是实现
# importing libraries
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys
class Window(QMainWindow):
# list of numbers
number = [2, 3, 6, 9, 8, 12, 16, 7, 10, 5, 4, 11, 2, 13]
def __init__(self):
super().__init__()
# setting title
self.setWindowTitle("Linear search ")
# setting geometry
self.setGeometry(100, 100, 600, 400)
# calling method
self.UiComponents()
# showing all the widgets
self.show()
# method for widgets
def UiComponents(self):
# start flag
self.start = False
# list to hold labels
self.label_list = []
# desired value
self.desired = 11
# counter for keeping index
self.counter = 0
# local counter
c = 0
# iterating list of numbers
for i in self.number:
# creating label for each number
label = QLabel(str(i), self)
# adding background color and border
label.setStyleSheet("border : 1px solid black;
background : white;")
# aligning the text
label.setAlignment(Qt.AlignTop)
# setting geometry using local counter
# first parameter is distance from left
# and second is distance from top
# third is width and forth is height
label.setGeometry(50 + c * 30, 50, 20, i * 10 + 10)
# adding label to the label list
self.label_list.append(label)
# incrementing local counter
c = c + 1
# creating push button to start the search
self.search_button = QPushButton("Start Search", self)
# setting geometry of the button
self.search_button.setGeometry(100, 270, 100, 30)
# adding action to the search button
self.search_button.clicked.connect(self.search_action)
# creating push button to pause the search
pause_button = QPushButton("Pause", self)
# setting geometry of the button
pause_button.setGeometry(100, 320, 100, 30)
# adding action to the search button
pause_button.clicked.connect(self.pause_action)
# creating label to show the result
self.result = QLabel("To search : " + str(self.desired), self)
# setting geometry
self.result.setGeometry(350, 280, 200, 40)
# setting style sheet
self.result.setStyleSheet("border : 3px solid black;")
# adding font
self.result.setFont(QFont('Times', 10))
# setting alignment
self.result.setAlignment(Qt.AlignCenter)
# creating a timer object
timer = QTimer(self)
# adding action to timer
timer.timeout.connect(self.showTime)
# update the timer every 200 millisecond
timer.start(200)
# method called by timer
def showTime(self):
# checking if flag is true
if self.start:
# linear search
# checking if the element is equal to desired element
if self.label_list[self.counter].text() == str(self.desired):
# make its color green
self.label_list[self.counter].setStyleSheet(
"border : 1px solid black;
background : lightgreen;")
# show result in result label
self.result.setText("Found at index : "
+ str(self.counter))
# make the start flag false
self.start = False
# reseting the counter
self.counter = 0
# if element is not equal
else:
# make the label color grey
self.label_list[self.counter].setStyleSheet(
"border : 1px solid black;
background : grey;")
# increment the counter
self.counter += 1
# if counter value become equal to list length
if self.counter == len(self.label_list):
# make start flag false
self.start = False
# show result i.e not found
self.result.setText("Not Found")
# method called by search button
def search_action(self):
# making flag true
self.start = True
# showing text in result label
self.result.setText("Started searching...")
# method called by pause button
def pause_action(self):
# making flag false
self.start = False
# showing text in result label
self.result.setText("Paused")
# create pyqt5 app
App = QApplication(sys.argv)
# create the instance of our Window
window = Window()
# start the app
sys.exit(App.exec())
输出 ：