Python Parameters In Quotes

Parametric equations express the coordinates of the points of a curve as functions of a variable, called a parameter. They make it easy to draw curves because you can just plug parameters into equations to produce a curve.

One downfall of numpy’s optimization of vector operations is that it only occurs on one operation at a time. That is to say, when we are doing the operation A * B + C with numpy vectors, first the entire A * B operation completes, and the data is stored in a temporary vector; then this new vector is added with C. The in-place version of the diffusion code in Example 6-14 shows this quite explicitly. However, there are many modules that can help with this. numexpr is a module that can take an entire vector expression and compile it into very efficient code that is optimized to minimize cache misses and temporary space used. In addition, the expressions can utilize multiple CPU cores (see Chapter 9 for more information) and specialized instructions for Intel chips to maximize the speedup. It is very easy to change code to use numexpr: all that’s required is to rewrite the expressions as strings with references to local variables. The expressions are compiled behind the scenes (and cached so that calls to the same expression don’t incur the same cost of compilation) and run using optimized code. Example 6-19 shows the simplicity of changing the evolve function to use numexpr. In this case, we chose to use the out parameter of the evaluate function so that numexpr doesn’t allocate a new vector to which to return the result of the calculation.

A value being passed to a function in a function call is an argument. The argument 'Al' is assigned to a local variable named name. Variables that have arguments assigned to them are parameters.

myname) The name of this function is testfunc. It has a single parameter, myname, and its body is the block of code immediately following the line beginning with def (short for define). A parameter is a variable that

dictionary packing/unpacking, which transforms a list of function parameters into a dictionary and vice versa.

In case an exception (Exceptions will be discussed in Chapter 7: Exceptions.) occurs during the execution of the with block, the exc_type, exc_value, and traceback parameters hold the class of the exception, the exception itself, and the exception’s traceback attribute, respectively.

Lambda expressions in Python are defined using the keyword lambda, followed by a list of parameters separated by commas, a colon (:), and an expression that represents the return value of the function call.

a static method is a method that belongs to a class rather than any instance of the class. It does not require access to the class or its instances, so it neither takes a reference to the instance (self) nor to the class (cls) as a parameter.

Class methods are instance methods on the class object. This means they take a reference to the class object as their first parameter (cls)

print(i, end=" ")  # 3 5 7 9 The end parameter in the print() function specifies the character or string to print at the end of the output, replacing the default newline (\n).

In Python, a common convention for marking unused parameters in functions is to name them _, __, ___, and so on, for each unused parameter. def func(_, __, ___, x):

Variable argument lists for functions and methods are also available in Python, indicated by the * symbol. However, unlike Java, in Python, the function receives the parameters as a tuple, not as an array

Please note that default parameter values are evaluated only once when the function is defined, not every time the function is called.

In Python, the / symbol is used in function definitions to indicate that parameters preceding it are positional-only. This means they can only be specified by position and cannot be passed as keyword arguments. Parameters following the / are either positional-only or positional-or-keyword. def func(a, b, c, /, d, e):     print(a, b, c, d, e) func(1, 2, 3, 4, 5)  # 1 2 3 4 5 func(6, 7, 8, 9, e=10)  # 6 7 8 9 10 # This does not work # func(6, 7, c=8, d=9, e=10)

Instead, the constructor and every method within a class need to have at least one parameter, conventionally named self. Python automatically passes the object instance as the first argument when you call a method on an object.

Python does not support method overloading based on different parameter types. Instead, you can utilize default parameter values and conditional logic within the method to achieve similar functionality.

To achieve functionality similar to having multiple constructors in Java, you can use default parameter values and variable-length argument lists.