Comparing strings with numbers - Python

Question

I can't figure out why the following code gives a True, False, True result.

print("3" < "4")
print("3" < "10")
print("3" < "30")

I understand the 1st and 3rd code but why doesn't the print("3" < "10") give a True response.

thanks

Answer 1

From the python docs on comparison operations:

Strings are compared lexicographically using the numeric equivalents (the result of the built-in function ord()) of their characters.

The character comparison starts with the first character and steps through the strings being compared until a character difference is found.

Your 2nd statement returns False since:

ord("3") > ord ("1")

Answer 2

The link suggested will give you elaborate answer. However since I am assuming that you are beginning programming, I am trying to take a very simple approach to explain.

For strings, as soon as you start writing:

 "ab"<"bc"

 "30"<"400"

Imagine this:

['a', 'b'] <['b', 'c']
['3', '0'] <['1', '0', '0']

Now the comparison is made on the first elements of both list and only moves to next element if they are equal:

The first one should be True. The second one should be False.

Follow the same logic and try:

'30'<'31'

It should evaluate to True.