Computer Science for STEM: The PreTeXt Interactive Edition

Glossary Glossary

collection data type.

A data type in which the values are made up of components, or elements, that are themselves values.

default value.

The value given to an optional parameter if no argument for it is provided in the function call.

dot notation.

Use of the dot operator, ., to access functions inside a module, or to access methods and attributes of an object.

immutable data type.

A data type whose values cannot be changed. Modifying functions create a totally new object that does not change the original one.

index.

A variable or value used to select a member of an ordered collection, such as a character from a string, or an element from a list.

indexing ([]).

Access a single character in a string using its position (starting from 0). Example: 'This'[2] evaluates to 'i'.

length.

Number of characters in a string. It can be found by (len) function Example: len('happy') evaluates to 5.

optional parameter.

A parameter written in a function header with an assignment to a default value which it will receive if no corresponding argument is given for it in the function call.

slice.

A part of a string (substring) specified by a range of indices. More generally, a subsequence of any sequence type in Python can be created using the slice operator (sequence[start:stop]). Example: 'bananas and cream'[3:6] evaluates to ana (so does 'bananas and cream'[1:4]).

whitespace.

Any of the characters that move the cursor without printing visible characters. The constant string.whitespace contains all the white-space characters.