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What does the caret (^) character mean?
...
The ^ (caret) can also be used when specifying ranges.
To exclude commits reachable from a commit, a prefix ^ notation is
used. E.g. ^r1 r2 means commits reachable from r2 but exclude the ones
reachable from r1.
<rev>
Include commits that are reach...
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...
What is the best way to concatenate two vectors?
...ation. The boost::join function
http://www.boost.org/doc/libs/1_43_0/libs/range/doc/html/range/reference/utilities/join.html
will give you this.
std::vector<int> v0;
v0.push_back(1);
v0.push_back(2);
v0.push_back(3);
std::vector<int> v1;
v1.push_back(4);
v1.push_back(5);
v1.push_back...
Flatten nested dictionaries, compressing keys
... this to all key-paths of the tree.
>>> reduce(lambda a,b:(a,b), range(5))
((((0, 1), 2), 3), 4)
Demonstration (which I'd otherwise put in docstring):
>>> testData = {
'a':1,
'b':2,
'c':{
'aa':11,
'bb':22,
'cc':{
...
boost Composite keys - C/C++ - 清泛网 - 专注C/C++及内核技术
... Whites
std::pair<phonebook::iterator,phonebook::iterator> p=
pb.equal_range(boost::make_tuple(std::string("White")));
On the other hand, partial searches without specifying the first keys are not allowed.
By default, the corresponding std::less predicate is used for each subkey of a compo...
Why unsigned integer is not available in PostgreSQL?
...ble origin of that question. The desire for unsigned ints is to double the range of ints with the same number of bits, it's an efficiency argument, not the desire to exclude negative numbers, everybody knows how to add a check constraint.
When asked by someone about it, Tome Lane stated:
Basic...
What do we mean by Byte array? [closed]
... byte, the second byte etc..
Just as bytes can encode different types and ranges of data (numbers from 0 to 255, numbers from -128 to 127, single characters using ASCII e.g. 'a' or '%', CPU op-codes), each byte in a byte array may be any of these things, or contribute to some multi-byte values such...
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
share
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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.
...
Regular expression for letters, numbers and - _
...the character class definition, otherwise it has a different meaning (i.e. range). The . also has a different meaning outside character class definitions, but inside, it's just a literal .
References
regular-expressions.info/Anchors, Character Classes and Repetition
In PHP
Here's a snippet t...