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In Ruby on Rails, what's the difference between DateTime, Timestamp, Time and Date?
... is a bit more subtle: DATETIME is formatted as YYYY-MM-DD HH:MM:SS. Valid ranges go from the year 1000 to the year 9999 (and everything in between. While TIMESTAMP looks similar when you fetch it from the database, it's really a just a front for a unix timestamp. Its valid range goes from 1970 to 2...
remove_if equivalent for std::map
I was trying to erase a range of elements from map based on particular condition. How do I do it using STL algorithms?
13 A...
Operation on every pair of element in a list
...here order is irrelevant:
result = [foo(people[p1], people[p2]) for p1 in range(len(people)) for p2 in range(p1+1,len(people))]
In case you don't want to operate but just to get the pairs, removing the function foo and using just a tuple would be enough.
All possible pairs, including duplicate...
For every character in string
...
Looping through the characters of a std::string, using a range-based for loop (it's from C++11, already supported in recent releases of GCC, clang, and the VC11 beta):
std::string str = ???;
for(char& c : str) {
do_things_with(c);
}
Looping through the characters of a std...
Python Empty Generator Function
...ng a hard time coming up with a use case for this for which iter([]) or (x)range(0) wouldn't work equally well.
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Read first N lines of a file in python
...hon 2
with open("datafile") as myfile:
head = [next(myfile) for x in xrange(N)]
print head
Python 3
with open("datafile") as myfile:
head = [next(myfile) for x in range(N)]
print(head)
Here's another way (both Python 2 & 3)
from itertools import islice
with open("datafile") as myf...
How to remove gaps between subplots in matplotlib?
...date(wspace=0.025, hspace=0.05) # set the spacing between axes.
for i in range(16):
# i = i + 1 # grid spec indexes from 0
ax1 = plt.subplot(gs1[i])
plt.axis('on')
ax1.set_xticklabels([])
ax1.set_yticklabels([])
ax1.set_aspect('equal')
plt.show()
...
vector::at vs. vector::operator[]
...exceptional)...and bugs in the code (dereferencing iterator that is out of range is exceptional thing)
– Bojan Komazec
Feb 21 '12 at 10:52
...
Cartesian product of x and y array points into single array of 2D points
... cartesian_product_recursive(arrays[1:], out=out[0:m,1:])
for j in range(1, arrays[0].size):
out[j*m:(j+1)*m,1:] = out[0:m,1:]
return out
def cartesian_product_itertools(*arrays):
return numpy.array(list(itertools.product(*arrays)))
### Test code ###
name_func = [('rep...
initialize a numpy array
...ollows :
import numpy as np
big_array = [] # empty regular list
for i in range(5):
arr = i*np.ones((2,4)) # for instance
big_array.append(arr)
big_np_array = np.array(big_array) # transformed to a numpy array
of course your final object takes twice the space in the memory at the creatio...