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Understanding dict.copy() - shallow or deep?
...he dictionary is not copied by value, but just creating a new reference.
>>> a = {1: [1,2,3]}
>>> b = a.copy()
>>> a, b
({1: [1, 2, 3]}, {1: [1, 2, 3]})
>>> a[1].append(4)
>>> a, b
({1: [1, 2, 3, 4]}, {1: [1, 2, 3, 4]})
In contrast, a deep copy will co...
List of lists changes reflected across sublists unexpectedly
... @Allanqunzi you are wrong. Do x = 1000; lst = [x]*2; lst[0] is lst[1] -> True. Python does not distinguish between mutable and immutable objects here whatsoever.
– timgeb
Apr 17 '16 at 18:08
...
How to count the frequency of the elements in an unordered list?
...y from the list will get you the count as well as get rid of duplicates.
>>> a = [1,1,1,1,2,2,2,2,3,3,4,5,5]
>>> d = {x:a.count(x) for x in a}
>>> d
{1: 4, 2: 4, 3: 2, 4: 1, 5: 2}
>>> a, b = d.keys(), d.values()
>>> a
[1, 2, 3, 4, 5]
>>> b
[4, 4...
Access POST values in Symfony2 request object
... deprecated since 2.3 and will be removed in 3.0, see documentation
$form->getData();
gives you an array for the form parameters
from symfony2 book page 162 (Chapter 12: Forms)
[...] sometimes, you may just want to use a form without a class, and get back an array of the submitted
data. This is ...
How to convert comma-delimited string to list in Python?
...
You can use the str.split method.
>>> my_string = 'A,B,C,D,E'
>>> my_list = my_string.split(",")
>>> print my_list
['A', 'B', 'C', 'D', 'E']
If you want to convert it to a tuple, just
>>> print tuple(my_list)
('A', 'B', '...
python pandas dataframe to dictionary
...this command will lose data if there redundant values in the ID columns: >>> ptest = p.DataFrame([['a',1],['a',2],['b',3]], columns=['id', 'value']) >>> ptest.set_index('id')['value'].to_dict()
– dalloliogm
Jun 23 '14 at 11:32
...
Accessing elements of Python dictionary by index
...the keys. Getting the dictionary stored under "Apple", do the following:
>>> mydict["Apple"]
{'American': '16', 'Mexican': 10, 'Chinese': 5}
And getting how many of them are American (16), do like this:
>>> mydict["Apple"]["American"]
'16'
...
Process escape sequences in a string in Python
...orrect thing to do is use the 'string-escape' code to decode the string.
>>> myString = "spam\\neggs"
>>> decoded_string = bytes(myString, "utf-8").decode("unicode_escape") # python3
>>> decoded_string = myString.decode('string_escape') # python2
>>> print(decod...
Laravel - Eloquent or Fluent random row
...
Laravel >= 5.2:
User::inRandomOrder()->get();
or to get the specific number of records
// 5 indicates the number of records
User::inRandomOrder()->limit(5)->get();
// get one random record
User::inRandomOrder()->first(...
Getting the caller function name inside another function in Python? [duplicate]
... third element in each record is the caller name. What you want is this:
>>> import inspect
>>> def f():
... print inspect.stack()[1][3]
...
>>> def g():
... f()
...
>>> g()
g
For Python 3.5+, each frame record is a named tuple so you need to replac...