53
votes
13
answers
932
views
How do I read CSV data into a record array in NumPy?
I wonder if there is a direct way to import the contents of a CSV file into a record array, much in the way th
60
votes
11
answers
1.4K
views
Most efficient way to map function over numpy array
What is the most efficient way to map a function over a numpy array? The way I've been doing it in my cur
47
votes
30
answers
798
views
How to count the occurrence of certain item in an ndarray?
In Python, I have an ndarray y that is printed as array([0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1]) I'm trying
65
votes
5
answers
2.6K
views
What are the advantages of NumPy over regular Python lists?
What are the advantages of NumPy over regular Python lists? I have approximately 100 financial markets series
54
votes
17
answers
1.3K
views
Is there a NumPy function to return the first index of something in an array?
I know there is a method for a Python list to return the first index of something: >>> l = [1, 2, 3]
68
votes
11
answers
1.3K
views
What does -1 mean in numpy reshape?
A numpy matrix can be reshaped into a vector using reshape function with parameter -1. But I don't know w
47
votes
8
answers
1.7K
views
How to access the ith column of a NumPy multidimensional array?
Suppose I have: test = numpy.array([[1, 2], [3, 4], [5, 6]]) test[i] gets me ith line of the array (eg [1,
62
votes
15
answers
750
views
Convert pandas dataframe to NumPy array
I am interested in knowing how to convert a pandas dataframe into a NumPy array. dataframe: import numpy as
51
votes
20
answers
2.3K
views
How do I get indices of N maximum values in a NumPy array?
NumPy proposes a way to get the index of the maximum value of an array via np.argmax. I would like a similar
55
votes
22
answers
835
views
How can the Euclidean distance be calculated with NumPy?
I have two points in 3D: (xa, ya, za) (xb, yb, zb) And I want to calculate the distance: dist = sqrt((xa-xb)^
47
votes
11
answers
456
views
Dump a NumPy array into a csv file
Is there a way to dump a NumPy array into a CSV file? I have a 2D NumPy array and need to dump it in human-rea
57
votes
21
answers
1.9K
views
How to print the full NumPy array, without truncation?
When I print a numpy array, I get a truncated representation, but I want the full array. Is there any way to
56
votes
18
answers
2.3K
views
55
votes
11
answers
1.4K
views
Why is "1000000000000000 in range(1000000000000001)" so fast in Python 3?
It is my understanding that the range() function, which is actually an object type in Python 3, generates its
57
votes
29
answers
1.5K
views
How do I parse a string to a float or int?
In Python, how can I parse a numeric string like "545.2222" to its corresponding float value, 545.2222? Or par
54
votes
24
answers
2.6K
views
Converting string into datetime
I've got a huge list of date-times like this as strings: Jun 1 2005 1:33PM Aug 28 1999 12:00AM I&apos
52
votes
15
answers
3.1K
views
How to access environment variable values
I set an environment variable that I want to access in my Python application. How do I get its value?
58
votes
30
answers
500
views
60
votes
22
answers
2.4K
views
How do you change the size of figures drawn with Matplotlib?
How do you change the size of figure drawn with Matplotlib?
52
votes
30
answers
1.2K
views
How do you split a list into evenly sized chunks?
I have a list of arbitrary length, and I need to split it up into equal size chunks and operate on it. There a