Python
Python is a dynamic, strongly typed, object-oriented, multipurpose programming language, designed to be quick (to learn, to use, and to understand), and to enforce a clean and uniform syntax. Two similar but incompatible versions of Python are in use (Python 2.7 or 3.x). For version-specific Python questions, please also use the [python-2.7] or [python-3.x] tags. When using a Python variant (Jython, Pypy, Iron-python, etc.) - please also tag the variant.
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What are the differences between numpy arrays and matrices? Which one should I use?
What are the advantages and disadvantages of each? From what I've seen, either one can work as a replace
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Pandas conditional creation of a series/dataframe column
I have a dataframe along the lines of the below: Type Set 1 A Z 2 B Z
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Find nearest value in numpy array
Is there a numpy-thonic way, e.g. function, to find the nearest value in an array? Example: np.find_nearest
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What is the purpose of meshgrid in Python / NumPy?
Can someone explain to me what is the purpose of meshgrid function in Numpy? I know it creates some kind of gr
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Simple Digit Recognition OCR in OpenCV-Python
I am trying to implement a "Digit Recognition OCR" in OpenCV-Python (cv2). It is just for learning purposes. I
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Numpy array dimensions
I'm currently trying to learn Numpy and Python. Given the following array: import numpy as np a = np.arr
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Sorting arrays in NumPy by column
How can I sort an array in NumPy by the nth column? For example, a = array([[9, 2, 3], [4, 5, 6],
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Pandas read_csv low_memory and dtype options
When calling df = pd.read_csv('somefile.csv') I get: /Users/josh/anaconda/envs/py27/lib/pytho
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7
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pandas create new column based on values from other columns / apply a function of multiple columns, row-wise
I want to apply my custom function (it uses an if-else ladder) to these six columns (ERI_Hispanic, ERI_AmerInd
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How to find all occurrences of an element in a list
index() will give the first occurrence of an item in a list. Is there a neat trick which returns all indices i
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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
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11
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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
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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
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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
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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]
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11
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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
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8
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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,
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15
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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
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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
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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)^
