This Add Two Numbers lesson is for a beginner. Read the short notes, run each example, then change one name or number and run it again.
The + operator adds numbers. Text that looks like a number is still text until int or float converts it.
Adding two strings joins them. That is a different operation.
Example 1: Start here
int("3.5") fails. Use float when the text may contain a decimal point.
a = int("20") # text read as a whole number
b = int("4") # text read as a whole number
print(a + b)
Example 2: Add a list of fees
sum is the direct way to add every number.
print(sum([25000, 18000, 12000])) # add the numbers together
Example 3: Start from zero
The loop version shows the running total.
total = 0 # a whole number
for fee in [25000, 18000]: # repeat the indented lines once per value
total += fee # update the stored value
print(total)
Example 4: Skip the missing ones
Ignore None so a missing fee does not break the addition.
fees = [25000, None, 18000] # a list; the values stay in this order
total = sum(fee for fee in fees if fee is not None) # the total
print(total)
int("3.5") fails. Use float when the text may contain a decimal point.
