Error defining a function : <p>My task is to make o a function named count_nucleotides which takes to string, one word and a letter and counts the appearance number of the letter. For example:</p>

<p>count_nucleotides('ATCGGC', 'G') and gives 2</p>

<p>count_nucleotides('ATCTA', 'G') and gives 0</p>

<p>My code until now is below:</p>

<pre><code>def count_nucleotides(dna, nucleotide):

count = 0
num = nucleotide

for char in dna:
    if char = num:
        count = count +1
return count
</code></pre>

<p>It returns a message: expected an intended block</p>

<p>I am new at python proggramming so if someone could explain instead of asking question such as where  define this or that, i would be grateful. This is my first task so excuse me for what you see!</p>
