4.2: Built-in Functions
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Python provides a number of important built-in functions that we can use without needing to provide the function definition. The creators of Python wrote a set of functions to solve common problems and included them in Python for us to use.
min functions give us the largest and smallest values in a list, respectively:
>>> max('Hello world') 'w' >>> min('Hello world') ' ' >>>
max function tells us the "largest character" in the string (which turns out to be the letter "w") and the
min function shows us the smallest character (which turns out to be a space).
Another very common built-in function is the
len function which tells us how many items are in its argument. If the argument to
len is a string, it returns the number of characters in the string.
>>> len('Hello world') 11 >>>
These functions are not limited to looking at strings. They can operate on any set of values, as we will see in later chapters.
You should treat the names of built-in functions as reserved words (i.e., avoid using "max" as a variable name).