大约有 47,000 项符合查询结果（耗时：0.0459秒） [XML]
Difference between Big-O and Little-O Notation
... O(g) says, essentially
For at least one choice of a constant k > 0, you can find a constant a such that the inequality 0 <= f(x) <= k g(x) holds for all x > a.
Note that O(g) is the set of all functions for which this condition holds.
f ∈ o(g) says, essentially
For every c...
What is the reason for having '//' in Python? [duplicate]
...erands was already a floating point number.
In Python 2.X:
>>> 10/3
3
>>> # to get a floating point number from integer division:
>>> 10.0/3
3.3333333333333335
>>> float(10)/3
3.3333333333333335
In Python 3:
>>> 10/3
3.3333333333333335
>>> 1...
Deleting lines from one file which are in another file
...
answered Jan 24 '11 at 9:06
gabuzogabuzo
6,27833 gold badges2323 silver badges3535 bronze badges
...
Parse (split) a string in C++ using string delimiter (standard C++)
...>=tiger";
std::string delimiter = ">=";
std::string token = s.substr(0, s.find(delimiter)); // token is "scott"
The find(const string& str, size_t pos = 0) function returns the position of the first occurrence of str in the string, or npos if the string is not found.
The substr(size_t p...
Show a number to two decimal places
...):
return number_format((float)$number, 2, '.', '');
Example:
$foo = "105";
echo number_format((float)$foo, 2, '.', ''); // Outputs -> 105.00
This function returns a string.
share
|
improv...
AWK: Access captured group from line pattern
...
answered Jun 2 '10 at 12:50
Peter TillemansPeter Tillemans
33k99 gold badges7272 silver badges109109 bronze badges
...
dplyr: “Error in n(): function should not be called directly”
...
120
I presume you have dplyr and plyr loaded in the same session. dplyr is not plyr. ddply is not a ...
How to suppress scientific notation when printing float values?
...%f' % (x/y)
but you need to manage precision yourself. e.g.,
'%f' % (1/10**8)
will display zeros only.
details are in the docs
Or for Python 3 the equivalent old formatting or the newer style formatting
share
...
Replace values in list using Python [duplicate]
...
207
Build a new list with a list comprehension:
new_items = [x if x % 2 else None for x in items]
...
Get local IP address in node.js
... net of nets[name]) {
// skip over non-ipv4 and internal (i.e. 127.0.0.1) addresses
if (net.family === 'IPv4' && !net.internal) {
if (!results[name]) {
results[name] = [];
}
results[name].push(net.address);
}
}
...