Simple Python Data Victor Norman CS104 Calvin College

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Data Type (or “class”) Everything has a type – Defines legal values and the operations you can do on those values. – integers: values = whole numbers; operations: add, multiply, etc. – strings: series of characters; operations: upper- case it, append to it, etc. Python must know what type of thing it is dealing with, always.

Literal Values Code must provide hints as to what type of thing you mean: – all digits  integer (int) – all digits and a dot  floating point number (float) – characters surrounded by quotes  string (str) – more to come…

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String Literals Can use single, double, triple-single, or triple- double quotes: – ', ", ''', """ Triple quotes useful for creating strings with quotes in them and/or newlines in them. Examples…

Type Conversion Functions Useful when you have a value that is the wrong type. – Really only needed by us when we read in a value from the user (which is always a str) and need to treat it like an int or float. Takes a value and produces a value of another type. Do NOT do this kind of thing: – float(3.14) – int(3) – str(“hello”)

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Namespace and Objectspace Assignment creates/updates name in the namespace to refer to an object (new or existing) in the objectspace. Assignment steps: – evaluate the rhs (i.e., get a value for it) find object with that value or create it in objectspace. – Look up the name on lhs. if it does not exist, create it in the namespace. – Make name point to the value.

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Assignment for Thursday Do TuringsCraft CodeLab questions before lab on Thursday. – These are graded and finishing before lab is crucial. Note for TC assignment: – you can print out multiple items on one line this way: x = 3 y = 4 print(x, y) print(“Result is”, x * y)