Python Function Arguments

Your Python^® documentation shows you how to call a Python function. Python function signatures look similar to MATLAB^® function signatures. However, Python has syntax which might be unfamiliar to MATLAB users.

Positional Arguments

A positional argument is passed by position. These arguments appear at the beginning of a function signature.

Python Signature	MATLAB Usage
`abs(X)` Argument `X` is required.	`py.abs(-99)`

Some functions accept an arbitrary sequence of positional arguments, including no arguments. In Python, these arguments are defined by prepending the name with the * character.

Python Signature MATLAB Usage

Python Signature	MATLAB Usage
`itertools.izip(*iterables)` The `iterables` argument is not required, in which case, the function returns a zero length iterator.	Aggregate elements from two lists. `py.itertools.izip(... py.list({1:10}),py.list({'a','b'}));` Create zero length iterator. `py.itertools.izip;`

itertools.izip(*iterables)
The iterables argument is not required, in which case, the function returns a zero length iterator.

Aggregate elements from two lists.
py.itertools.izip(... py.list({1:10}),py.list({'a','b'}));

Create zero length iterator.
py.itertools.izip;

Keyword Arguments

A keyword argument is preceded by an identifier. Keyword arguments, also called named arguments, can be specified in any order.

Keyword arguments are like name-value pairs in MATLAB. Use the MATLAB pyargs function to create keyword arguments for Python functions.

Python Signature	MATLAB Usage
`print(*objects,sep='',end='\n', file=sys.stdout)` `sep`, `end`, and `file` are keyword arguments.	Change the value of `end`. `py.print('string',pyargs('end','--'))`

Python defines an arbitrary number of keyword arguments by prepending the name with ** characters.

Python Signature	MATLAB Usage
`dict(**kwarg)`	`D = py.dict(pyargs('Joe',100,'Jack',101))`

Optional Arguments

An optional argument is a non-required argument.

Python Signature	MATLAB Usage
`random.randrange(start,stop[,step])` Argument `step` is optional.	`py.random.randrange(1,100)`

Optional arguments can have default values. A default value is indicated by an equal sign = with the default value.

Python Signature	MATLAB Usage
`print(*objects,sep='',end='\n', file=sys.stdout)` The default value for `file` is `sys.stdout`.	Print two values using default keyword values. `py.print(2,'2')`

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