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Selecting pandas column by location
...oc or index based using .iloc method to do column-slicing including column ranges:
In [50]: import pandas as pd
In [51]: import numpy as np
In [52]: df = pd.DataFrame(np.random.rand(4,4), columns = list('abcd'))
In [53]: df
Out[53]:
a b c d
0 0.806811 0.18763...
Process escape sequences in a string in Python
...tin-1' codec can't encode character '\u0151'
in position 3: ordinal not in range(256)
Adding a regular expression to solve the problem
(Surprisingly, we do not now have two problems.)
What we need to do is only apply the unicode_escape decoder to things that we are certain to be ASCII text. In p...
Why does the C++ STL not provide any “tree” containers?
...don't make any sense for a hierarchy (anything that changes the order of a range, for example). Even defining a range within a hierarchy could be a messy business.
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Explain Morris inorder tree traversal without using stacks or recursion
... will visually display random binary trees
import binarytree as b
for _ in range(10):
print()
print("Example #",_)
tree=b.tree()
print(tree)
MorrisTraversal(tree)
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How to flatten only some dimensions of a numpy array
...
A slight generalization to Peter's answer -- you can specify a range over the original array's shape if you want to go beyond three dimensional arrays.
e.g. to flatten all but the last two dimensions:
arr = numpy.zeros((3, 4, 5, 6))
new_arr = arr.reshape(-1, *arr.shape[-2:])
new_arr.sh...
How to equalize the scales of x-axis and y-axis in Python matplotlib?
...er into the api to do this:
from matplotlib import pyplot as plt
plt.plot(range(5))
plt.xlim(-3, 3)
plt.ylim(-3, 3)
plt.gca().set_aspect('equal', adjustable='box')
plt.draw()
doc for set_aspect
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sed: print only matching group
...-7
Will result in output of:
2 3.4
-d sets the delimiter
-f selects the range of 'fields' to output, in this case, it's the 6th through 7th chunks of the original string. You can also specify the range as a list, such as 6,7.
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Printing Lists as Tabular Data
... Supports multi-line rows.
asciitable Asciitable can read and write a wide range of ASCII table formats via built-in Extension Reader Classes.
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What does %~dp0 mean, and how does it work?
...udes all leading spaces)
%~dn will return the drive letter of %n (n can range from 0 to 9) if %n is a valid path or file name (no UNC)
%~pn will return the directory of %n if %n is a valid path or file name (no UNC)
%~nn will return the file name only of %n if %n is a valid file name
%~xn ...
What's a quick way to comment/uncomment lines in Vim?
... which just runs any arbitrary vim commands at each line in your specified range. For example:
Commenting with #:
1. visually select the text rows (using V as usual)
2. :norm i#
This inserts "#" at the start of each line. Note that when you type : the range will be filled in, so it will really...