Is possible to construct a NumPy array from a python list?
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9 Answers
First of all, I'd recommend you to go through NumPy's Quickstart tutorial, which will probably help with these basic questions.
You can directly create an array from a list as:
import numpy as np
a = np.array( [2,3,4] )
Or from a from a nested list in the same way:
import numpy as np
a = np.array( [[2,3,4], [3,4,5]] )
you mean something like this ?
from numpy import array
a = array( your_list )
Comments
a = numpy.array([1,2,3])
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You want to save it as a file?
import numpy as np
myList = [1, 2, 3]
np.array(myList).dump(open('array.npy', 'wb'))
... and then read:
myArray = np.load(open('array.npy', 'rb'))
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You can use numpy.asarray, for example to convert a list into an array:
>>> a = [1, 2]
>>> np.asarray(a)
array([1, 2])
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I suppose, you mean converting a list into a numpy array? Then,
import numpy as np
# b is some list, then ...
a = np.array(b).reshape(lengthDim0, lengthDim1);
gives you a as an array of list b in the shape given in reshape.
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Here is a more complete example:
import csv
import numpy as np
with open('filename','rb') as csvfile:
cdl = list( csv.reader(csvfile,delimiter='\t'))
print "Number of records = " + str(len(cdl))
#then later
npcdl = np.array(cdl)
Hope this helps!!
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import numpy as np
... ## other code
some list comprehension
t=[nodel[ nodenext[i][j] ] for j in idx]
#for each link, find the node lables
#t is the list of node labels
Convert the list to a numpy array using the array method specified in the numpy library.
t=np.array(t)
This may be helpful: https://numpy.org/devdocs/user/basics.creation.html
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maybe:
import numpy as np
a=[[1,1],[2,2]]
b=np.asarray(a)
print(type(b))
output:
<class 'numpy.ndarray'>
