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I have a variable data that is of (1000L, 3L) shape and I do the following to get the coordinates:
x = data[:,0]
y = data[:,1]
z = data[:,2]
Is there a way to unpack them? I tried but it doesn't work:
[x,y,z] = data1[:,0:3]
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Introduction. Unpacking in Python refers to an operation that consists of assigning an iterable of values to a tuple (or list ) of variables in a single assignment statement. As a complement, the term packing can be used when we collect several values in a single variable using the iterable unpacking operator, * .
To unpack elements of a uint8 array into a binary-valued output array, use the numpy. unpackbits() method in Python Numpy. The result is binary-valued (0 or 1). The axis is the dimension over which bit-unpacking is done.
If you want to unpack the first few elements of a list and don't care about the other elements, you can: First, unpack the needed elements to variables. Second, pack the leftover elements into a new list and assign it to another variable.
In Python we can also destructure ( unpack) items from a list (Python doesn't have a native array data structure but a list looks identical to a Javascript array). The syntax would look like so: We can skip items in the list, just like in Javascript.
What’s unpacking? Unpacking is the process of getting out stuff — iterables such as lists, tuples, and dictionaries. Think of it as opening a box and getting out different items like cables, headphones, or a USB. Unpacking in Python is similar to unpack a box in real life. Let’s translate this same example into code for a better understanding:
We can unpack a unique element of an iterable. For example, you’d come up with something like this: If we want to unpack all the values of an iterable to a single variable, we must set up a tuple, hence adding a simple comma will be enough:
In python tuples can be unpacked using a function in function tuple is passed and in function values are unpacked into normal variable. Consider the following code for better understanding. Writing code in comment?
You could unpack using zip:
x, y, z = zip(*data[:, :3])
You could simply transpose it before unpacking:
x, y, z = data.T
Unpacking "unpacks" the first dimensions of an array and by transposing the your array the size-3 dimension will be the first dimension. That's why it didn't work with [x, y, z] = data1[:, 0:3] because that tried to unpack 1000 values into 3 variables.
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