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Are tuples more efficient than lists in Python?
...l code, but that assigning a tuple is much faster than assigning a list.
>>> def a():
... x=[1,2,3,4,5]
... y=x[2]
...
>>> def b():
... x=(1,2,3,4,5)
... y=x[2]
...
>>> import dis
>>> dis.dis(a)
2 0 LOAD_CONST 1 (1)
...
Can an Android Toast be longer than Toast.LENGTH_LONG?
...uration == Toast.LENGTH_LONG ? LONG_DELAY : SHORT_DELAY);
}
and default values for duration are
private static final int LONG_DELAY = 3500; // 3.5 seconds
private static final int SHORT_DELAY = 2000; // 2 seconds
sha...
How to elegantly rename all keys in a hash in Ruby? [duplicate]
...
ages = { 'Bruce' => 32, 'Clark' => 28 }
mappings = { 'Bruce' => 'Bruce Wayne', 'Clark' => 'Clark Kent' }
ages.transform_keys(&mappings.method(:[]))
#=> { 'Bruce Wayne' => 32, 'Clark Kent' => 28 }
...
Convert to binary and keep leading zeros in Python
...
Use the format() function:
>>> format(14, '#010b')
'0b00001110'
The format() function simply formats the input following the Format Specification mini language. The # makes the format include the 0b prefix, and the 010 size formats the output...
python capitalize first letter only
... first character is an integer, it will not capitalize the first letter.
>>> '2s'.capitalize()
'2s'
If you want the functionality, strip off the digits, you can use '2'.isdigit() to check for each character.
>>> s = '123sa'
>>> for i, c in enumerate(s):
... if not ...
Printing tuple with string formatting in Python
...
>>> thetuple = (1, 2, 3)
>>> print "this is a tuple: %s" % (thetuple,)
this is a tuple: (1, 2, 3)
Making a singleton tuple with the tuple of interest as the only item, i.e. the (thetuple,) part, is the key ...
List comprehension rebinds names even after scope of comprehension. Is this right?
...lly fixed in Python 3.
This means that in all of:
list(x for x in a if x>32)
set(x//4 for x in a if x>32) # just another generator exp.
dict((x, x//16) for x in a if x>32) # yet another generator exp.
{x//4 for x in a if x>32} # 2.7+ syntax
{x: x//16 for x in a if x...
PHP Multidimensional Array Searching (Find key by specific value)
...ion myfunction($products, $field, $value)
{
foreach($products as $key => $product)
{
if ( $product[$field] === $value )
return $key;
}
return false;
}
share
|
improve ...
Apply pandas function to column to create multiple new columns?
...
I usually do this using zip:
>>> df = pd.DataFrame([[i] for i in range(10)], columns=['num'])
>>> df
num
0 0
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
>>> def powers(x):
>>> return x, x*...
Python Dictionary Comprehension
...nd values, although of course you can specify a dummy value if you like.
>>> d = {n: n**2 for n in range(5)}
>>> print d
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16}
If you want to set them all to True:
>>> d = {n: True for n in range(5)}
>>> print d
{0: True, 1: True, 2: ...