如何搜索字符串中重複的字符？

Question

我想寫一個函數，檢查重複字符串中的字符，如果發現重複，則輸出false。像'hello16'或'secret77'就是無效的密碼。

我有什麼到目前爲止

Answer 1

一個非常簡單的解決辦法是這樣：

def password_check(pw): 
    if len(pw) < 2: 
     print ('Password must be at least 2 characters long') 
     return False 
    elif pw.isalpha(): 
     print('Password must contain at least one number.') 
     return False 
    elif pw.isdigit(): 
     print('Password must contain at least one letter. ') 
     return False 
    for a in pw: 
     if a * 2 in pw: 
      print('Password contains a consecutive character') 
      return False 
    print('Password was accepted') 
    return True 

簡單地檢查是否有任何字符，其出現在密碼中連續存在兩次。

Answer 2

使用groupby：

from itertools import groupby 

def password_check(pw): 
    if not pw: 
     print('Please enter a password') 
    elif pw.isalpha(): 
     print('Password must contain at least one number.') 
    elif pw.isdigit(): 
     print('Password must contain at least one letter. ') 
    elif any((len(list(vals)) > 1) for (char, vals) in groupby(pw)): 
     print('Password cannot contain duplicate characters. ') 
    else: 
     print('True') 


pw = input('Enter new password: ') 
password_check(pw) # Call your function