Types of Things in Python

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What are Types

Almost from the beginning in programming you should have seen two different things in Python: text ( ex: "Hello World" ) and numbers ( ex: 4 ). You may or may not have seen that these 2 types of things cannot be added together. That makes sense, they are sort of apples and oranges. Numbers are actually more complicated because 4 and 4., for example, are not not quiet of the same type one is an integer one is a float. They can be added because that too makes sense, the answer will be 8. also a float.

So how do you tell what type something is? There is a function called type( xyz ) which will tell you what type of thing xyz is. Some examples.

what_type_1     = 4
what_type_2     = 4.
what_type_3     = 4 + 0j

print  "what_type_1", type( what_type_1 )
print  "what_type_2", type( what_type_2 )
print  "what_type_3", type( what_type_3 )

Types and Classes

Another lens to look at types is that of classes for types really are classes. What do I mean? In Python you can create new types which are called classes. A class is a software object which can be created and assigned to a variable. I will not go into the reasons why this is so great for programming ( it is part of Object Oriented Programming, you can gooogle it ) but will briefly show you how. It is a bit like defining a function. Note that you can more or less skim this code, there will be lots more on classes later.

Convert Object to String!

Almost any object can be converted to a string. This is done with the str() function. This can let you log information to a file, or print the object. Sometimes the string is useful ( it usually is for lists ) and sometimes not so much. Nice to know however.


Printing Objects

Pretty much any object can be printed. This may or may not be useful. Python first changes it to a string and then prints the string, see above.

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