Hi guys,

I am learning Pytohn for the last few months, and I have run into this website, which helped me a lot when I wasn't sure what isa actually happening in the code, since show every step in the exection: http://pythontutor.com/visualize.html#mode=display

For example, I had a simple code that counts characters in the sentence:

message = 'This is a sentence from which we will count the characters'
count = {}
for char in message:
count.setdefault(char, 0)
count[char] += 1
print(count)

I had trouble in understanding how it's exactly happening, until I ran it on the website and it was crystal clear: in every iteration, it goes through the sentence and checks if the current charactes is in the dictinary, if not, it adds it as a key, and sets his value to zero, if it is, it adds +1 to its value count. I know it's simple but until I REALLY got it, it was frustrating.

I hope you will also find it useful as well. Happy coding!

P.S Sorry if someone already posted it!