Python基础练习

# 随便输入一段字符串，计算整数的个数
info = input('>>>').strip()
for i in info:
    if i.isalpha():
        info = info.replace(i, " ")
l = info.split()
print(len(l))

# ab互换
a = 1
b = 2
a,b = b,a
print(a,b)

# 循环迭代字符串(不需要知道字符串多长)
s = "qwertyuiopasdfghjkl"
index = 0
while 1:
    print(s[index])
    index += 1
    if index == len(s):
        break
        
# 有如下值li= [11,22,33,44,55,66,77,88,99]，将所有小于 66 的值
保存至字典的第一个key中，将大于 66 的值保存至第二个key的值中。
即： {'k1': 小于66的所有值列表, 'k2': 大于66的所有值列表}
li = [11, 22, 33, 44, 55, 66, 77, 88, 99]
dic = {}
l_greater = [] #大于66的所有值列表
l_less = []    #小于66的所有值列表
for i in li:
    if i < 66:
        l_less.append(i)
    elif i > 66:
        l_greater.append(i)
dic.setdefault("k1", l_less)
dic.setdefault("k2", l_greater)
print(dic)

# 输出商品列表，用户输入序号，显示用户选中的商品
商品 li = ["手机", "电脑", '鼠标垫', '游艇']
要求：    1：页面显示 序号 + 商品名称，如：
            1 手机
            2 电脑
            ...
        2：用户输入选择的商品序号，然后打印商品名称
        3：如果用户输入的商品序号有误，则提示输入有误，并重新输入
        4：用户输入Q或者q，退出程序
flag = True
while flag:
    li = ["手机", "电脑", "鼠标垫", "游艇"]
    for i in li:
        print("{}	{}".format(li.index(i)+1, i))
    num_of_chioce = input("请输入选择的商品序号/输入Q或者q退出程序：")
    if num_of_chioce.isdigit():
        num_of_chioce = int(num_of_chioce)
        if num_of_chioce > 0 and num_of_chioce <= len(li):
            print(li[num_of_chioce-1])
        else:print("请输入有效数字")
    elif num_of_chioce.upper() == "Q":
        break
    else:
        print("请输入数字")
    
# 让用户选择何时退出
x = ""
while x != "quit":
    x = input("如果想退出，请输入quit(不区分大小写:").lower()
    if x != "quit":        #退出成功时不再打印输入内容
        print(x)

active = True
while active:
    g_input = input("如果想退出，请输入quit(不区分大小写):").lower()
    if g_input == "quit":
        active = False
    else:
        print(g_input)
        
# 使用用户输入来填充字典
dic = {}    #定义一个空字典
active = True   #设置一个标志
while active:
    name = input("您叫什么名字？")
    response = input("请问您喜欢什么户外运动？")
    dic[name] = response    #名字和答案以键值对存储进字典
    repeat = input("非常感谢您的配合!任意键退出/修改请输入yes：")
    repeat = repeat.lower()     #大小写不区分
    if repeat != "yes":
        active = False
for name, response in dic.items():      #遍历字典
    print("
姓名：" + name + "
爱好：" + response)      #换行打印
    
# 注册、保存账号密码、3次机会验证登录    
while 1:
    name = input("请输入注册账号：")
    password = input("请输入注册密码：")
    confirm_password = input("请再一次确认密码：")
    if confirm_password == password:
        print("恭喜您注册成功")
        with open("text", mode="w+", encoding="utf-8") as file:
            file.write("{}
{}".format(name, password))
        break
    else:
        continue
i = 0
lis = []
while i < 3:
    use = input("请输入登录账号：")
    psd = input("请输入登录密码：")
    with open("text", mode="r+", encoding="utf-8") as file:
        for x in file:
            lis.append(x)
    if use == name and psd == password:
        print("登录成功")
        break
    else:
        print("登录失败")
    i += 1
    
# 用户输入内容，计算"索引为奇数且对应的元素为数字"的个数
content = input(">>>:")
count = 0
for i in range(len(content)):
    if i % 2 != 0 and content[i].isdigit():
        count += 1
print(count)

# 有列表lis = [1, 2, 3, 4, 5, 7, 8, 9],将所有小于6的值保存至字典
的key1中,将大于6的值保存至字典的key2中
lis = [1, 2, 3, 4, 5, 7, 8, 9]
result = {"key1": [], "key2": []}
for i in lis:
    if i < 6:
        if "key1" not in result:
            result["key1"] = []
        result["key1"].append(i)
    else:
        if "key2" not in result:
            result["key2"] = []
        result["key2"].append(i)
print(result)

lis = [1, 2, 3, 4, 5, 7, 8, 9]
result = {}
result.setdefault("key1", [])
result.setdefault("key2", [])
for i in lis:
    if i < 6:
        result["key1"].append(i)
    else:
        result["key2"].append(i)
print(result)

# 移除列表lis每个元素的空格、找出以"A"或者"a"开头、并以"c"结尾的所有元素，将这些元素添加到新列表中
lis = ["taibai", "alexC", "AbC", "egon", "Ritian", "Wusir", " aqc"]
lis1 = []
lis2 = []
lis3 = []
for i in lis:
    lis1.append(i.strip())
print(lis1)
for i1 in lis1:
    if i1.startswith("A") or i1.startswith("a"):
        lis2.append(i1)
for i2 in lis2:
    if i2.endswith("c"):
            lis3.append(i2)
print(lis3)

# 写程序：模拟公司HR录入员工账号密码的程序
1)员工的账号密码存储在这种数据类型中
user_list = [{"username": "barry", "password": "1234"}
             {"username": "ppd", "password": "123456"}
               .....................................  ]
2)非法字符模板：board = ["张三", "李小四", "王二麻子"]
3)HR输入用户名、密码（可持续输入，如果想终止程序，那就在输入用户名时输入Q或者q），在
HR输入用户名时，检测此用户名是否有board里面的非法字符，如果有非法字符，则将非法字符替
换成同数量的*，然后添加到user_list中，如果没有非法字符，则直接添加到user_list中，每次
添加成功后，打印出刚添加的用户名、密码。
user_list = []
board = ["张三", "李小四", "王二麻子"]
while 1:
    u_name = input("请输入用户名、退出程序请输入Q或者q:")
    if u_name.upper() == "Q":
        break
    for i in range(len(board)):
        if u_name == board[i]:
            u_name = len(board[i])*"*"
    ps_wd = input("请输入用户密码:")
    user_list.append({"username": u_name, "password": ps_wd})
    print(user_list)
    
# 写函数，判断用户传入的值（字符串、列表、元组）的长度是否大于5
def s_lenth(s):
    if len(s) > 5:
        return "right"
ret = s_lenth("123456")
print(ret)
    
# 写函数，检查用户传入的对象（字符串、列表、元组）的每一个元素是否含有空内容，并返回结果
def func(x):
    if type(x) is str:
        for i in x:
            if i == ' ':
                return True
    elif x and type(x) is list or type(x) is tuple:
        for i in x:
            if not i:
                return True
    elif not x:
        return True
print(func())

# 写函数，用户传入修改的文件名，与要修改的内容，执行函数，完成整个文件的批量修改操作
import os
def alter_content(file, old_str, new_str):
    """
    将替换的字符串写到一个新的文件中，然后将原文件删除，新文件改为原来文件的名字
    file: 文件路径
    old_str: 需要替换的字符串
    new_str: 替换的字符串
    return: None
    """
    with open(testfile, "r", encoding="utf-8") as f1, open("%s.bak" % testfile, "w", encoding="utf-8") as f2:
        for line in f1:
            if old_str in line:
                line = line.replace(old_str, new_str)
            f2.write(line)
    os.remove(testfile)
    os.rename("%s.bak" % testfile, testfile)
alter_content("test", "你好", "测试")
     
# 两个数相乘，计算结果保留2位小数
a = eval(input())
b = eval(input())
print("面积是:%.5f" % (a*b))

# 斐波那锲数列1,1,2,3,5,8,13...根据这样的规律，求出400
万以内最大的斐波那锲数，并求出是第几个斐波那锲数
def count(a, b):
    n = 0
    while b < 4000000:
        a, b = b, a+b
        n = n + 1
    return n, a                
count(0, 1)               

# 求第n个斐波那锲数
def recursion(n):
    if n <= 2:
        return 1
    return recursion(n-1)+recursion(n-2)
recursion(5)

# 处理文件，用户指定要查找的文件和内容，将文件中包含要查找内容的每一行都输出到屏幕
def check_file(filename,check_content):
    with open(filename, encoding="utf-8") as f:
        for i in f:
            if check_content in i:
                yield i
generator = check_file("text", "id")
for i in generator:
    print(i)    
                    
# 如下，每个小字典的name对应股票名字，shares对应多少股，price对应股票的价格。
计算购买每支股票的总价        
portfolio = [{'name': 'IBM', 'shares': 100, 'price': 91.1},
             {'name': 'AAPL', 'shares': 50, 'price': 543.22},
             {'name': 'FB', 'shares': 200, 'price': 21.09},
             {'name': 'HPQ', 'shares': 35, 'price': 31.75},
             {'name': 'YHOO', 'shares': 45, 'price': 16.35},
             {'name': 'ACME', 'shares': 75, 'price': 115.65}]
res = map(lambda dic:{dic["name"]:round(dic["shares"]*dic["price"], 2)},portfolio)        
    
# 用递归实现阶乘        
def factorial(n):
    print(n)
    if n == 0:  #等于0就运算完了
        return 1
    return n * factorial(n - 1)  #每次递归相乘，n值都比之前小1
res = factorial(4)
print(res)        
                
# 随意写一个n行以上的文件
1.运行程序，先将内容读到内存中，用列表存储
2.接收用户输入页码，每页5条，仅输出当页的内容    
def check_content(filename):
    with open(filename, "r", encoding="utf-8") as f:
        lis = f.readlines()
        pages, row = divmod(len(lis), 5)
        if row:
            pages += 1
        while True:
            page_num = input("请输入页码或者输入Q/q退出:")
            if page_num.isdigit():
                page_num = int(page_num)
                if page_num <= 0 or page_num > pages:
                    print("33[31;1m超出页码范围,请重新输入:33[0m")
                elif page_num == pages and row !=0:
                    for i in range(row):
                        print(lis[(page_num - 1) * 5 + i].strip())
                else:
                    for i in range(5):
                        print(lis[(page_num-1)*5 +i].strip())
            elif page_num.lower() == "q":
                print("33[32;1m退出成功33[0m")
                break
            else:
                print("输入有误,请重新输入:")
                continue
check_content("text")
        
import re
data = {"time": "2016-80-05T13:13:05",
        "grp1": {"fld1": 1, "fld2": 2},
        "xxx2": {"fld3": 0, "fld5": 0.4},
        "fld6": 11,
        "fld7": 7,
        "fld46": 8}
lis = []
for k in data.keys():
    lis.append(str(k))
for v in data.values():
    lis.append(str(v))
ret = re.findall("fld[d]*", str(lis))
ret = "|".join(ret)
print(ret)  # fld7|fld46|fld6|fld1|fld2|fld3|fld5        
        
# *************************************************    
import re

def deal_sign(expre_str):
    """处理表达式中的 +- 或 -- """
    exp_str = expre_str.replace("+-", "-")
    exp_str = expre_str.replace("--", "+")
    return exp_str

def cal_exp_min(exp_min):
    """计算最小化的表达式（两个数之间的乘除）"""
    if "*" in exp_min:
        x, y = exp_min.split("*")
        return str(float(x)*float(y))
    elif "/" in exp_min:
        x, y = exp_min.split("/")
        return str(float(x) / float(y))

def deal_express_no_bracket(express_no_bracket):
    """ 处理没有括号的表达式
        exp_no_bra是没有经过处理的最内层带括号的表达式"""
    exp = express_no_bracket.strip("()")
    print("3:  " + exp)
    # 先乘除后加减
    # -40/5*8+2
    while True:
        ret = re.search("d+.?d*[*/]-?d+.?d*", exp)
        if ret:  # True说明表达式中还有乘除法
            exp_min = ret.group()  # 得到最简单的表达式
            print("4:  " + exp_min)
            ret_min = cal_exp_min(exp_min)  # 调用
            print("5:  " + ret_min)
            exp = exp.replace(exp_min, ret_min)
            exp = deal_sign(exp)
        else:
            ret = re.findall("-?d+.?d*", exp)
            sum = 0
            for i in ret:
                sum = sum + float(i)
                print("结果：", sum)
            return str(sum)

def remove_bracket(express_str):
    """提取括号里面没有括号的表达式"""
    while True:
        ret = re.search("([^()]+)", express_str)
        if ret:
            express_no_bracket = ret.group()
            print("2:  " + express_no_bracket)
            new_ret = deal_express_no_bracket(express_no_bracket)  # 调用
            print("6:  " + new_ret)  # replace(2, 6)
            express_str = express_str.replace(express_no_bracket, new_ret)
            print("7:  " + express_str)
            exp_str = deal_sign(express_str)  # 调用
            print("8:  " + exp_str)
        else:
            print(exp_str)
            ret = deal_express_no_bracket(exp_str)
            return ret

def cal_express():
    """去空格"""
    express_str = input("请输入要计算的表达式：")
    express_str = express_str.replace(" ", "")
    print("1:  " + express_str)
    remove_bracket(express_str)

if __name__ == "__main__":
    cal_express()