python

Python:

- split returns a splited dict/ list
- append adds to ans empty array, list
- print "%.nf" ; n spefies precision upto n decimal spaces
- map() =>
	>>> squares = []
	>>> for x in range(10):
	...     squares.append(x**2)
	>>> squares
	[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

	same as

	squares = [x**2 for x in range(10)]
	or
	squares = map(lambda x: x**2, range(10))

- map(function f, sequence s,....):
	it returns the sequence of type s(default list) modified by the function f.
	[IMP! IT CAN TAAKE MORE THAN 1 SEQUENCES]
	eg: map(int, "1 3 5") returns a list [1, 3, 5]   etc..

- tuple(list) makes a tuple from the list

- x.strip([char]) strips of the end charcters, char, from  the list/string x, (default whitespaces)211

- filter(function, sequence) returns a sequence consisting of those items from the sequence for which function(item) is true.
[imp! IT TAKES ONLY 2 ARGS,.. INSTEAD USE LIST COMPREHENSION, see line 49]

- reduce(function, sequence) returns a single value constructed by calling the binary function function on the first two items of the sequence, then on the result and the next item (similar to recursion)

- in module __future__ ,
	print(item, sep = , end = )

	also for int div: a//b and for decimal div a/b

- lamda x :  similar to #define macros

- map() consumes more time than for loop.

- sorted(data_type) returns the same data_type sorted.

- print(time.time()) : prints the time the prom took from its begin to run.

- lists can be:
	index and slice , append  , delete from , sort  and reverse .

- List Comprehensions: derived from map:
	sq = [a**2 for a in range(5)]
	op = [[x,y,z] for x in range(a+1) for y in range(b+1) for z in range(c+1) if x+y+z!=n]

(ref: https://docs.python.org/2/tutorial/datastructures.html; 5.1.3)

- sorted(list_to_sort, key=itemgetter(2,0,1))
	import: from operator import itemgetter
	also:
	l.sort(key=lambda x: x[2])

- join():  The method join() returns a string in which the string elements of sequence have been joined by str separator.
	str.join(seq/list)


STRINGS:

- str.swapcase() : swaps the case of each letter in a str


GTK :

ELements/ Wigdets
- window
- button

- First add padding to you window to make it clean
	window.set_border_width(px)


- add(elm) to add the elem
- signals in Gtk : (use connect to connect them to functions)
	windows => delete-event,
	button => clicked ,

- Box :  Gtk.Box(orentation="eg. Gtk.Orentation.HORIZONTAL", spacing=" eg. 100 ")
	->

- Grid layout :  Gtk.Grid()
	-> can be refered by rows and cols
	-> grid.attach(elmenent, column, row, width/col_span, height/row_span )
	-> grid atatch_next_to( elem_to_add, ref_elem, position        , width, height )
												   Gtk.Postion.BOTTOM
												   Gtk.Postion.RIGHT
												   Gtk.Postion.LEFT

- ListBox: Gtk.ListBox() [a box f very helpful for forms]
	-> listbox.set_selection_mode(Gtk.Seelction.NONE) ==> SO as to allow user to selct nothing (also can use .MULTIPLE)
	-> create rows in ListBox by using Gtk.ListBoxRow(), use .add() to add elem to it
	-> CheckBox: Gtk.CheckButton()	Adds a mcq waala check box
	-> ToggleSwitch : Gtk.Switch() 	Adds 1/0 switch

- Stack + StackSwitcher :  Gtk.Stack() and Gtk.StackSwitcher()
	-> Initiale the stack:
		stack.set_transition_type(Gtk.StackTranstionType.SLIDE_LEFT_RIGHT)
		stack.set_transiton_duration(in ms)
	-> to add elem to a stack var in a new stack
		stack.add_titled(elem, "id", "Stack Name")
	-> to add stck switcher
		switcher = Gtk.StackSwitcher()


- Odd stuff : 
	New-style classes inherit from object, or from another new-style class.

			class NewStyleClass(object):
			    pass

			class AnotherNewStyleClass(NewStyleClass):
			    pass

	Old-style classes don't.

			class OldStyleClass():
			    pass

	super() doesn't work with old style classes. As :
		>>instance = OldStyleClass()
		>>issubclass(instance.__class__, object)
		False

	instead use :
		class OldStyleClass(AnotherOldClass, object):
	so as to have NewStyleClass functionality/.

	Or use C++ style inheritance.