Value won't increment inside while loop
<p>my problem is that the 'month' value increments once to month = 1, then stays there the whole time, causing an infinite loop. How do I get this to change every time through the loop? I know I'm probably missing something extremely simple. </p>

<pre><code>def rem_bal(balance, annualInterestRate, monthlyInterestRate):
    month = 0 
    while month &lt;= 12:
        monthly_interest = (annualInterestRate) / 12.0
        minimum_monthly = (monthlyInterestRate) * balance
        monthly_unpaid= (balance) - (minimum_monthly)
        updated_balance = round(((monthly_unpaid) + (monthly_interest * monthly_unpaid)), 2)
        month =+ 1 
        print("Month " + str(month) + "Remaining balance: " + str(updated_balance) + " .")
        balance = updated_balance
    return balance
</code></pre>

<pre><code>month += 1
</code></pre>

<p>not </p>

<pre><code>month = +1
</code></pre>

<p>which is just </p>

<pre><code>month = 1
</code></pre>

python python-3.x while-loop