How to convert a list to an array in Python
During programming, there will be instances when you will need to convert existing lists to arrays in order to perform certain operations on them [arrays enable mathematical operations to be performed on them in ways that lists do not].
Lists can be converted to arrays using the built-in functions in the Python numpy library.
numpy provides us with two functions to use when converting a list into an array:
numpy.array[]
numpy.asarray[]
1. Using numpy.array[]
This function of the numpy library takes a list as an argument and returns an array that contains all the elements of the list. See the example below:
2. Using numpy.asarray[]
This function calls the numpy.array[] function inside itself. See the definition below:
def asarray[a, dtype=None, order=None]: return array[a, dtype, copy=False, order=order]The main difference between np.array[] and np.asarray[] is that the copy flag is false in the case of np.asarray[], and true [by default] in the case of np.array[].
This means that np.array[] will make a copy of the object [by default] and convert that to an array, while np.asarray[] will not.
The code below illustrates the usage of np.asarray[]: