pyton-异常、文件的读取、CSV,OS

1、测试写入中文

#1测试写入中文
f=open(r"c:/Users/FYL/Desktop/a.txt","w")
f.write("尚学堂\n百战程序员\n")
f.close()
#使用异常机制管理文件对象的关闭操作
try:
    f=open(r"e.txt","w")
    strs=["aa","cc","bb"]
    f.writelines(strs)
except BaseException as e:
    print(e)
finally:
    f.close()
# 2.文本文件的读取工作read,readline,readlines
#read
with open("e.txt","r",encoding="utf-8") as f:
    str=f.read()
    print(str)
with open("e.txt","r",encoding="utf-8") as f:
    for a in f:
        print(a,end="")
#3.enumerate
a=["我love u","尚学堂\n","百战程序员\n"]
b=enumerate(a)
print(a)
print(list(b))
#4.推导式
with open("e.txt","r",encoding="utf-8") as f:
    lines=f.readlines()
    lines=[line.rstrip()+" #"+str(index+1)+'\n' for index,line in enumerate(lines)]#推导式生成列表
print(lines)
with open("e.txt","w",encoding="utf-8")as f:
    f.writelines(lines)
#5,二进制文本的操作
with open("dog.jpg","rb") as f:
    with open("copy_dog.jpg","wb") as w:
        for lines in f.readlines():
            w.write(lines)
print("图片拷贝完成")
#6.文件对象的常用方法和属性
#seek
with open("e.txt","r",encoding="utf-8") as f:
    print("文件名是:{0}".format(f.name))
    print(f.tell())#读取指针当前的位置
    print("读取的内容：{0}".format(f.readline()))
    print(f.tell())
    print(f.seek(3))
    print("读取的内容：{0}".format(f.readline()))
#7.pickle对象序列化
import pickle
a1="赵薇"
a2=234
a3=[10,20,30]
with open("data.dat","wb") as f:
    pickle.dump(a1,f)
    pickle.dump(a2,f)
    pickle.dump(a3,f)
with open("data.dat","rb") as f:
    b1=pickle.load(f)
    b2=pickle.load(f)
    b3=pickle.load(f)
    print(b1)
    print(b2)
    print(b3)

2、测试异常

#1测试异常
print("step0")
try:
    print("step1")
    a = 1 / 0
    print("step2")
except BaseException as e:
    print("发生异常step3")
    print(e)
    print(type(e))
print("step4")
#例子循环输入数字，如果不是数字则处理异常，直到输入88，则结束循环
while True:
    try:
        x=input("请输入一个数字")
        print("输入的数字;",x)
        if x==88:
            print("退出程序")
            break
    except BaseException as e:
        print("出现异常")
        print(e)
print("程序结束")
try:
    a=input("请输入一个被除数")
    b=input("请输入一个除数")
    c=float(a)/float(b)
except BaseException as e:
    print(e)
else:
    print(c)
finally:
    print("无论是否发生异常，我都会执行")
print("程序结束")
# 打开文件
try:
    f = open("c:/Users/FYL/Desktop/a.txt", "r")
    content = f.readline()
    print(content)
except:
    print("未找到文件")
finally:
    print()
    f.close()
print("程序执行结束")
# 2.with上下文管理
with open("c:/Users/FYL/Desktop/a.txt") as f:
    content = f.readline()
    print(content)
print("程序执行结束")


# 3.定义异常类
class AgeError(Exception):
    def __init__(self, errorInfo):
        Exception.__init__(self)
        self.errorIofo = errorInfo

    def __str__(self):
        return str(self.errorIofo) + "年龄错误"


###### 测试代码 ########
if __name__ == "__main__":  # 如果为True，则模块作为独立文件运行，可以执行测试代码
    age = int(input("输入一个年龄"))
    if age < 1 or age > 150:
        raise AgeError(age)
    else:
        print("正常的年龄：", age)

3.csv文件的操作读取和写入

import csv
with open("dd.csv","r")as f:
    a_csv=csv.reader(f)
    #print(list(a_csv))
    for row in a_csv:
        print(row)


with open("ee.csv","w")as f:
    b_csv=csv.writer(f)
    b_csv.writerow(["ID","姓名","年龄"])
    c=[["1004","嘻嘻","3"],["1005","东东","4"]]
    b_csv.writerows(c)

4.os模块调用操作系统文件和命令和os.path模块

import os
import os.path
os.system("notepad.exe")#调用记事本程序
os.startfile(r"E:\Software\QQ\Bin\QQScLauncher.exe")
#1.1 os模块-文件和目录操作
#1.1.1获取文件夹的相关属性
print(os.name)
print(os.sep)#分隔符
print(repr(os.linesep))#换行符
print(os.stat("test1.py"))#获取文件内容
#1.1.2关于工作目录的操作
print(os.getcwd())#获取当前的目录
os.chdir("d:")#改变当前的目录：d盘目录
os.mkdir("书籍")#然后建立了书籍文件夹
#1.1.3创建目录、创建多级目录、删除
os.rmdir("书籍")#相对路径都是相对当前的工作目录
os.makedirs("电影/港台/周星驰")#在多级目录建立文件夹
os.removedirs("电影/港台/周星驰")#只能删除空目录
os.makedirs("../音乐/香港/刘德华")#..是指的是在上一级目录建立文件夹
os.rename("电影","movie")#把文件电影重命名为movie
dirs=os.listdir("movie")#列出一级子目录一级文件夹
print(dirs)
#1.2对路径的操作
path=os.path.abspath("a.txt")
print(os.path.split(path))
# 列出工作目录下所有的.py文件，并输出文件名
path=os.getcwd()#获得当前目录
file_list=os.listdir(path)
for filename in file_list:
    if filename.endswith("py"):
        print(filename)
print("#########")
#列表式
filelist2=[filename for filename in os.listdir(path)if filename.endswith("py")]
for f in filelist2:
    print(f,end="\t")
#1.3.walk()递归遍历所有的文件和目录
#os.walk()方法
all_file=[]
path=os.getcwd()
file2=os.walk(path)
for dirpath,dirname,filename in file2:
    for dir in dirname:
#        print(dir)
        all_file.append(os.path.join(dirpath,dir))
    for name in filename:
        all_file.append(os.path.join(dirpath,name))
for file in all_file:
    print(file)
#shutil模块（拷贝和压缩）
import shutil
shutil.copyfile("1.txt","1_copy.txt")
shutil.copytree("movie/港台","电影")
shutil.make_archive("电影/gg","zip","movie/港台")
#zip压缩\解压缩
import zipfile
z1=zipfile.ZipFile("d:/a.zip","w")
z1.write("1.txt")
z1.close()

z2=zipfile.ZipFile("d:/a.zip","r")
z2.extractall("电影")
z2.close()

5.递归算法

num=1
def a1():
    global num#如果在函数内部改变全局变量的值，增加global关键字声明一下
    num+=1
    print("打印a")
    if num<3:
        a1()
def b1():
    print("b1")
a1()
#使用递归计算n的阶乘
def factorial(n):
    if n==1:
        return n
    else:
        return n*factorial(n)
factorial(5)
#递归打印所有的目录和文件
import os
def getAllFile(path):
    childFile=os.listdir(path)
    for file in childFile:
        filepath=os.path.join(path,file)
        if os.path.isdir(filepath):
            getAllFile(filepath)
        print(filepath)
getAllFile("Day_1")