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How to add a new row to an empty numpy array
... proper dimensionality.
>>> arr
array([], shape=(0, 3), dtype=int64)
Then be sure to append along axis 0:
arr = np.append(arr, np.array([[1,2,3]]), axis=0)
arr = np.append(arr, np.array([[4,5,6]]), axis=0)
But, @jonrsharpe is right. In fact, if you're going to be appending in a loop,...
How do I check which version of NumPy I'm using?
...David CDavid C
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What is “loose coupling?” Please provide examples
... answered Oct 22 '08 at 18:35
64BitBob64BitBob
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How do I make JavaScript beep?
...
Solution
You can now use base64 files to produce sounds when imported as data URI. The solution is almost the same as the previous ones, except you do not need to import an external audio file.
function beep() {
var snd = new Audio("data:audio/wav;b...
Read a zipped file as a pandas DataFrame
...In [12]: crime2013
Out[12]:
<class 'pandas.core.frame.DataFrame'>
Int64Index: 24567 entries, 0 to 24566
Data columns (total 15 columns):
CCN 24567 non-null values
REPORTDATETIME 24567 non-null values
SHIFT 24567 non-null va...
You must enable the openssl extension to download files via https
... Where is this line? In which file? the php.ini in 1, C:\wamp64\bin\apache OR 2. C:\wamp64\bin\php\php7.0.0 ?
– MyDaftQuestions
Apr 3 '16 at 14:54
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Creating an empty Pandas DataFrame, then filling it?
...C': 'xyz'}, ignore_index=True)
df.dtypes
A object # yuck!
B float64
C object
dtype: object
Dealing with object columns is never a good thing, because pandas cannot vectorize operations on those columns. You will need to do this to fix it:
df.infer_objects().dtypes
A int64
B fl...
Lambda function in list comprehensions
...(map(lambda x: x*x, range(10))) will give you [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]
– rrlamichhane
Jun 12 at 22:58
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Getting key with maximum value in dictionary?
...50, 56: 20, 57: 33,
58: 20, 59: 33, 60: 20, 61: 20, 62: 108, 63: 108, 64: 7, 65: 28, 66: 28, 67: 28,
68: 15, 69: 15, 70: 15, 71: 103, 72: 23, 73: 116, 74: 23, 75: 15, 76: 23, 77: 23,
78: 36, 79: 36, 80: 10, 81: 23, 82: 111, 83: 111, 84: 10, 85: 10, 86: 31, 87: 31,
88: 18, 89: 31,...
Mapping two integers to one, in a unique and deterministic way
... * (A + B + 1) / 2 + A;
(-32768, -32768) => 8589803520 which is Int64. 64 bit output for 16 bit inputs may be so unpardonable!!
Szudzik's function:
A = a >= 0 ? 2 * a : -2 * a - 1;
B = b >= 0 ? 2 * b : -2 * b - 1;
A >= B ? A * A + A + B : A + B * B;
(-32768, -32768) => 4...