python小象學院: 判斷字符串/文件讀寫操作/break/class封裝-----判斷密碼強弱

1.項目描述

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2.判斷字符串:含有數字,字母等

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3.break與continue區別

 

for i in range(100):
    if i%2==0:
        break
    print(i)

for i in range(100):
    if i%2==0:
        continue
    print(i)

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 4.文件操作

 

 w  每次都重寫一遍

a  保存上一次的信息

"""
    auther:
    version:v6.0  python3.0
    date:2019.4.6
    fuction:Determine password strength
    Use:1.break 2.Limit the number of passwords set
    3.Save the password and the corresponding strength to the file
"""


def check_number_exist(password_srt):
    has_number = False
    for c in password_srt:
        if c.isnumeric():
            has_number = True
            break
    return has_number

def check_letter_exist(password_srt):
    has_letter = False
    for c in password_srt:
        if c.isalpha():
            has_letter = True
            break
    return has_letter

def main():

    try_time = 5

    while try_time > 0:

        password = input('Please enter a password:')

        strengtg_level = 0
        if len(password) >= 8:
            strengtg_level += 1
        else:
            print ('Password length is at least 8 digits!')

        if check_number_exist(password):
            strengtg_level += 1
        else:
            print ('Password must contain numbers!')

        if check_letter_exist(password):
            strengtg_level += 1
        else:
            print ('Password must contain letter!')
        s = 0
        if strengtg_level == 1:
            s = 'Weak password'
        elif strengtg_level == 2:
            s= 'Middle password'
        elif strengtg_level == 3:
            s = 'Strong password'
        f = open('password_3.0.txt','a')
        f.write('password:{},strength:{}\n'.format(password,s))
        f.close()
        if strengtg_level == 3:
            print ('Congratulations, the password strength is qualified.')
            # f = open('password_3.0.txt','a')
            # f.write(password)
            # f.close
            break

        else:
            print ('Unsatisfactory password strength.')
            try_time -= 1

        print()

    if try_time <= 0:
        print('Too many attempts to set password failed.')

if __name__=='__main__':
    main()

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5.面向對象編程

"""
    auther:
    version:v6.0  python3.0
    date:2019.4.12
    fuction:Determine password strength
    New additions:
    1.break
    2.Limit the number of passwords set
    3.Save the password and the corresponding strength to the file
    4.Read the password saved in the file
    5.Define a password class
    6.Define a file_tool
"""

class PasswordTool:

    def __init__(self,password):
        #Class attribute
        self.passwprd = password
        self.strength_level = 0

    def process_password(self):
        if len(self.passwprd) >= 8:
            self.strength_level += 1
        else:
            print ('Password length is at least 8 digits!')

        if self.check_number_exist():
            self.strength_level += 1
        else:
            print ('Password must contain numbers!')

        if self.check_alpha_exist():
            self.strength_level += 1
        else:
            print ('Password must contain letter!')


    #Class method
    def check_number_exist(self):
        has_number = False
        for c in self.passwprd:
            if c.isnumeric():
                has_number = True
                break
        return has_number

    def check_alpha_exist(self):
        has_letter = False
        for c in self.passwprd:
            if c.isalpha():
                has_letter = True
                break
        return has_letter

class FileTool:
    def __init__(self,filepath):
        self.filepath = filepath

    def write_to_file(self,line):
        f = open(self.filepath,'a')
        f.write(line)
        f.close()

    def read_from_file(self):
        f = open(self.filepath,'r')
        lines = f.readlines()
        f.close()
        return lines


def main():

    try_time = 5
    filepath = 'password_6.0.txt'
    file_tool = FileTool(filepath)
    while try_time > 0:

        password = input('Please enter a password:')
        #Instantiated object
        password_tool = PasswordTool(password)
        password_tool.process_password()


        line = 'password:{},strength:{}\n'.format(password, password_tool.strength_level)
        file_tool.write_to_file(line)

        if password_tool.strength_level == 3:
            print ('Congratulations, the password strength is qualified.')
            # f = open('password_3.0.txt','a')
            # f.write(password)
            # f.close
            break

        else:
            print ('Unsatisfactory password strength.')
            try_time -= 1

        print()

    if try_time <= 0:
        print('Too many attempts to set password failed.')
    lines = file_tool.read_from_file()
    print(lines)


if __name__=='__main__':
    main()