Python语言的特点有:
易于学习:语法和结构简单,学习起来更加简单。
易于阅读:Python代码定义更清晰。
易于维护:源代码是相当容易维护的。
广泛的标准库:Python的最大的优势之一是丰富的库,跨平台的,在UNIX,Windows和Macintosh兼容很好。
可移植:基于其开放源代码的特性,Python已经被移植(也就是使其工作)到许多平台。
可嵌入: 可以将Python嵌入到C/C++程序,让你的程序的用户获得"脚本化"的能力。
Python语法结构特点:
Python 是一种解释型语言: 这意味着开发过程中没有了编译这个环节。类似于PHP和Perl语言。
Python 是交互式语言: 这意味着,您可以在一个Python提示符,直接互动执行写你的程序。
Python 是面向对象语言: 这意味着Python支持面向对象的风格或代码封装在对象的编程技术。
Python 是初学者的语言:Python 对初级程序员而言,是一种伟大的语言,它支持广泛的应用程序开发,从简单的文字处理到 WWW 浏览器再到游戏。
读取带有表头的文件,转化为字典形式
#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# Author:Du Fei
index =0
myKey=[]
allList=[]
with open("person.txt","r") as f:
for one in f:
oneDict={}
if index == 0:#当前读取的数据是第一条
myKey =one.strip("\n").split(",")
index = 1
else:
oneList=one.strip("\n").split(",")
oneDict[myKey[0]]=oneList[0]
oneDict[myKey[1]]=int(oneList[1])
oneDict[myKey[2]]=float(oneList[2])
allList.append(oneDict)
print(allList)
Python实战
python简单实现学生管理系统
项目要求:
(1)显示所有学生信息
(2)新增一个学生信息
(3)修改学生的年龄
(4)根据学号删除学生
(5)按照姓名查找
(6)按照学号进行升序和降序排列
(7)功能菜单:该功能菜单供用户选择相应功能,调用上述不同功能模块
(8)数据从文件中读取
(9)将数据保存到文件中
一、使用python函数模块实现
#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# Author:Du Fei
import os
#学号,姓名,年龄,性别,身高
allStudentsList=[]
#从文件中读取数据
def readFromFile(fileName):
if not os.path.exists(fileName):# 如果文件不存在,则新增一个空文件
f = open(fileName,"w")
f.close()
with open(fileName,"r",encoding="utf-8") as f:
for onStr in f:
oneList=onStr.strip("\n").split(",")
oneList[0]=int(oneList[0])#学号
oneList[1]=oneList[1]#姓名
oneList[2]=int(oneList[2])#年龄
oneList[3]=oneList[3]#性别
oneList[4]=float(oneList[4])#身高
allStudentsList.append(oneList)
#将数据写入文件
def writeToFile(fileName):
f =open(fileName,"w")
f.close()
with open(fileName,"a",encoding="utf-8") as f:
for oneList in allStudentsList:
oneStr=str(str(oneList[0])+","+oneList[1]+","+str(oneList[2])+","+oneList[3]+","+str(oneList[4])+"\n")
f.write(oneStr)
#显示所有学生信息
def allStudentsShow():
for one in allStudentsList:
print("学号:%d,姓名:%s,年龄:%d,性别:%s,身高:%f" % (one[0], one[1], one[2], one[3],one[4]))
#新增学生
def addNewStudent(newStuList):
#check学号是否重复复
for one in allStudentsList:
if one[0] == newStuList[0]:
return -1 #学号重复
allStudentsList.append(newStuList)
writeToFile("student.txt")
return 1
#修改学生年龄
def updateStudentsAge(id,newAge):
for one in allStudentsList:
if one[0]==id:
one[2]=newAge
break
else:
return -1#找不到此学号
writeToFile("student.txt")
return 1
#删除学生
def deleteStudent(id):
index =0
for one in allStudentsList:
if one[0] ==id:
del allStudentsList[index]
break
index +=1
else:
return -1#找不到要删除的学号
writeToFile("student.txt")
return 1
#按照姓名查找
def searchStudents(name):
flag =0
for one in allStudentsList:
if one[1]==name:
print("学号:%d,姓名:%s,年龄:%d,性别:%s,身高:%f" % (one[0], one[1], one[2], one[3], one[4]))
flag=1
if flag==0:
return -1#查无此人
return 1
def sortMe(oneList):
return oneList[0]
#按序号排序
def orderById(flag):#flag:1升序,2降序
if flag==1:#升序
allStudentsList.sort(reverse=False,key=lambda oneList:oneList[0])
else:
allStudentsList.sort(reverse=True,key=sortMe)
#功能菜单
def menuShow():
print("**********************************")
print("*1.查看所有学生信息****************")
print("*2.新增学生************************")
print("*3.修改学生************************")
print("*4.删除学生************************")
print("*5.按姓名查找**********************")
print("*6.按学号排序**********************")
print("*7.保存***************************")
print("*8.退出***************************")
print("**********************************")
if __name__ == "__main__":
#从文件中读取数据
readFromFile("student.txt")
# print(allStudentsList)
while True:
# 显示主菜单
menuShow()
select =int(input("请选择功能选项:"))
if select == 1:
allStudentsShow()
elif select == 2:
while True:
try:
id = int(input("请输入学号:"))
name = input("请输入姓名:")
age = int(input("请输入年龄:"))
sex = input("请输入性别:")
height = float(input("请输入身高:"))
newStuList=[id,name,age,sex,height]
if addNewStudent(newStuList) ==-1:
print("学号已存在,请重新输入")
else:
flag=input("新增用户成功,是否继续新增(y/n)?:")
if flag.lower() !="y":
break
except:
print("输入有误请重新输入")
elif select == 3:
while True:
id=int(input("请输入序号:"))
newAge=int(input("请输入新的年龄:"))
if updateStudentsAge(id,newAge) ==-1:
print("找不到此学号的学生,请重新输入")
else:
flag = input("修改成功,是否继续修改(y/n)?:")
if flag.lower() != "y":
break
elif select == 4:
while True:
id =int(input("请输入删除的学号:"))
if deleteStudent(id) == -1:
print("找不到此学号的学生,请重新输入")
else:
flag = input("删除成功,是否继续删除(y/n)?:")
if flag.lower() != "y":
break
elif select == 5:
while True:
name=input("请输入查找的姓名:")
if searchStudents(name) ==-1:
print("查无此人")
flag = input("是否继续查找(y/n)?:")
if flag.lower() != "y":
break
elif select == 6:
flag=int(input("请选择排序方式(1:升序,2:降序)"))
orderById(flag)
allStudentsShow()
elif select == 7:
writeToFile("student.txt")
else:
exit()
二、使用python类模块实现
#!/usr/bin/env python
# -*- coding: UTF-8 -*-
# Author:Du Fei
import os
#生成学生类
class Student:
def __init__(self,id,name,age,sex,height):
self.id =id
self.name=name
self.age=age
self.sex =sex
self.height=height
def printMe(self):
print("学号:%d,姓名:%s,年龄:%d,性别:%s,身高:%f" % (self.id, self.name, self.age, self.sex, self.height))
#管理类
class StudentsManage:
def __init__(self):
self.allStudentsList =[]
#显示所有学生的信息
def allStudentsShow(self):
for one in self.allStudentsList:
one.printMe()
#新增学生
def addNewStudent(self,newStuList):
# check学号是否重复复
for one in self.allStudentsList:
if one.id == newStuList.id:
return -1 #学号重复
self.allStudentsList.append(newStuList)
return 1
# 修改学生年龄
def updateStudentsAge(self,id, newAge):
for one in self.allStudentsList:
if one.id == id:
one.age = newAge
break
else:
return -1 # 找不到此学号
return 1
#删除学生
def deleteStudent(self,id):
index =0
for one in self.allStudentsList:
if one.id ==id:
del self.allStudentsList[index]
break
index +=1
else:
return -1#找不到要删除的学号
return 1
#按照姓名查找
def searchStudents(self,name):
flag =0
for one in self.allStudentsList:
if one.name==name:
one.printMe()
flag=1
if flag==0:
return -1#查无此人
return 1
# 按序号排序
def orderById(self,flag): # flag:1升序,2降序
if flag == 1: # 升序
self.allStudentsList.sort(reverse=False, key=lambda x: x.id)
else:
self.allStudentsList.sort(reverse=True, key=lambda x: x.id)
# 从文件中读取数据
def readFromFile(self,fileName):
if not os.path.exists(fileName): # 如果文件不存在,则新增一个空文件
f = open(fileName, "w")
f.close()
with open(fileName, "r", encoding="utf-8") as f:
for onStr in f:
oneList = onStr.strip("\n").split(",")
oneList[0] = int(oneList[0]) # 学号
oneList[1] = oneList[1] # 姓名
oneList[2] = int(oneList[2]) # 年龄
oneList[3] = oneList[3] # 性别
oneList[4] = float(oneList[4]) # 身高
stu = Student(int(oneList[0]),oneList[1],int(oneList[2]),oneList[3],float(oneList[4]))
self.allStudentsList.append(stu)
# 将数据写入文件
def writeToFile(self,fileName):
f = open(fileName, "w")
f.close()
with open(fileName, "a", encoding="utf-8") as f:
for one in self.allStudentsList:
oneStr = str(one.id) + "," + one.name + "," + str(one.age) + "," + one.sex + "," + str(one.height) + "\n"
f.write(oneStr)
# 功能菜单
def menuShow():
print("**********************************")
print("*1.查看所有学生信息****************")
print("*2.新增学生************************")
print("*3.修改学生************************")
print("*4.删除学生************************")
print("*5.按姓名查找**********************")
print("*6.按学号排序**********************")
print("*7.保存***************************")
print("*8.退出***************************")
print("**********************************")
if __name__ == "__main__":
stManage=StudentsManage()
#从文件中读取数据
stManage.readFromFile("student.txt")
# print(allStudentsList)
while True:
# 显示主菜单
menuShow()
select =int(input("请选择功能选项:"))
if select == 1:
stManage.allStudentsShow()
elif select == 2:
while True:
try:
id = int(input("请输入学号:"))
name = input("请输入姓名:")
age = int(input("请输入年龄:"))
sex = input("请输入性别:")
height = float(input("请输入身高:"))
stu = Student(id,name,age,sex,height)
if stManage.addNewStudent(stu) ==-1:
print("学号已存在,请重新输入")
else:
flag=input("新增用户成功,是否继续新增(y/n)?:")
if flag.lower() !="y":
break
except:
print("输入有误请重新输入")
elif select == 3:
while True:
id=int(input("请输入序号:"))
newAge=int(input("请输入新的年龄:"))
if stManage.updateStudentsAge(id,newAge) ==-1:
print("找不到此学号的学生,请重新输入")
else:
flag = input("修改成功,是否继续修改(y/n)?:")
if flag.lower() != "y":
break
elif select == 4:
while True:
id =int(input("请输入删除的学号:"))
if stManage.deleteStudent(id) == -1:
print("找不到此学号的学生,请重新输入")
else:
flag = input("删除成功,是否继续删除(y/n)?:")
if flag.lower() != "y":
break
elif select == 5:
while True:
name=input("请输入查找的姓名:")
if stManage.searchStudents(name) ==-1:
print("查无此人")
flag = input("是否继续查找(y/n)?:")
if flag.lower() != "y":
break
elif select == 6:
flag=int(input("请选择排序方式(1:升序,2:降序)"))
stManage.orderById(flag)
stManage.allStudentsShow()
elif select == 7:
stManage.writeToFile("student.txt")
else:
exit()