In python, how do you check if a string has both uppercase and lowercase letters
<p>I've looked at the other post similar to my question, <a href="http://stackoverflow.com/questions/36380351/password-check-python-3">Password check- Python 3</a>, except my question involves checking if the password contains both uppercase and lower case questions. My code is the following, but when executed it fails to recognize that both lower and upper case letters are in the password, it only recognizes one type. How would I get it to recognize both types? Also is there an easier way to have the code check if all of those values occur without having to make functions for each individual step?</p>

<pre><code>def Get_Password():
    return input("Enter your desired password: ")

def Count_Digits(password):
    return sum(character.isdigit() for character in password)

def Valid_password_length(password):
    if len(password) &gt;= 10:
        return ('step1' == True)
    else:
        return ('step1' == False, print("Invalid password: too short"))

def Valid_password_characters(password):
    if password.isalnum():
        return ('step2' == True)
    else:
        return ('step2' == False, print("Invalid password: illegal character detected"))

def Valid_password_numdigit(password):
    if Count_Digits(password) &gt;= 2:
        return ('step3' == True)
    else:
        return ('step3' == False, print("Invalid password: Must have at least 2 digits"))

def Valid_password_lowercase(password):
    for i in (password):
        if i.islower() == True:
            return ('step4' == True)
        else:
            return ('step4' == False, print("Invalid password: No lowercase characters detected"))

def Valid_password_uppercase(password):
    for i in (password):
        if i.isupper() == True:
            return ('step5' == True)
        else:
            return ('step5' == False, print("Invalid password: No uppercase characters detected"))

def password_checker():
    password = Get_Password()
    Valid_password_length(password)
    Valid_password_characters(password)
    Valid_password_numdigit(password)
    Valid_password_lowercase(password)
    Valid_password_uppercase(password)

    if 'step1' and 'step2' and 'step3' and 'step4' and 'step5' == True:
        print("Congratulations! This password is valid")

password_checker()
</code></pre>

<p>Your question is simple to answer. You are returning things of the form <code>return('steps' == True)</code> which is always going to return false. So just replace those with <code>return True</code> or <code>return False</code>.</p>

<p>Assuming you fix the above, your looping is also buggy. You only want to return false after you have looped through the entire string. Consider the password: <code>ABCd</code>. This contains a lowercase character but your check lowercase method would return false because the first letter is uppercase. You want to look through every character in password and if none of those are lowercase, then return false.</p>

<p>If you want a neater way to do it, <a href="http://stackoverflow.com/a/39991194/5718020">cdlane's answer</a> is a nice pythonic way.</p>

python string