def signup(user_accounts, log_in, username, password):

'''

This function allows users to sign up.

If both username and password meet the requirements:

- Updates the username and the corresponding password in the user_accounts dictionary.

- Updates the log_in dictionary, setting the value to False.

- Returns True.

If the username and password fail to meet any one of the following requirements, returns False.

- The username already exists in the user_accounts.

- The password must be at least 8 characters.

- The password must contain at least one lowercase character.

- The password must contain at least one uppercase character.

- The password must contain at least one number.

- The username & password cannot be the same.

For example:

- Calling signup(user_accounts, log_in, "Brandon", "123abcABCD") will return False

- Calling signup(user_accounts, log_in, "BrandonK", "123ABCD") will return False

- Calling signup(user_accounts, log_in, "BrandonK","abcdABCD") will return False

- Calling signup(user_accounts, log_in, "BrandonK", "123aABCD") will return True. Then calling

signup(user_accounts, log_in, "BrandonK", "123aABCD") again will return False.

Hint: Think about defining and using a separate valid(password) function that checks the validity of a given password.

This will also come in handy when writing the change_password() function.

'''

if username not in user_accounts and valid(password) and username != password:

user_accounts.update([username:password])

log_ins.update([username:True])

return True

else

return False

def valid(password):

if len(password) < 8:

return False

elif any(x.isupper() for x in password) == True and any(y.islower() for y in password) == True and any(z.isdigit() for z in password) == True:

return True

# your code here