If you assign both variables on the same line, you actually get the same tuple.
t = (1, 2, 3); t1 = (1, 2, 3)
11.1 Tuples are Immutable , 11.2 Comparing Tuples , 11.4 Dictionaries and Tuples , 11.7 Using Tuples as Keys in Dictionaries
t = 'a', 'b', 'c', 'd', 'e'
t = ('a', 'b', 'c', 'd', 'e')
t = ('Ep', 'is', 'od', 'e ', 'III')
A tuple1 is a sequence of values much like a list. The values stored in a tuple can be any type, and they are indexed by integers. The important difference is that tuples are immutable. Tuples are also comparable and hashable so we can sort lists of them and use tuples as key values in Python dictionaries.,Lists are more common than tuples, mostly because they are mutable. But there are a few cases where you might prefer tuples:,However, since the list of tuples is a list, and tuples are comparable, we can now sort the list of tuples. Converting a dictionary to a list of tuples is a way for us to output the contents of a dictionary sorted by key:,Because tuples are immutable, they don't provide methods like sort and reverse, which modify existing lists. However Python provides the built-in functions sorted and reversed, which take any sequence as a parameter and return a new sequence with the same elements in a different order.
Syntactically, a tuple is a comma-separated list of values:
>>> t = 'a', 'b', 'c', 'd', 'e'
>>> t = ('a', 'b', 'c', 'd', 'e')
Without the comma Python treats
('a') as an expression with a string in parentheses that evaluates to a string:
>>> t2 = ('a') >>> type(t2) <type 'str'>
The output of the program is as follows:
['yonder', 'window', 'breaks', 'light', 'what', 'soft', 'but', 'in' ]
If you want to exit interactive mode, you can type:,There are five different standard data types in Python. They can further be grouped into two different object types: mutable and immutable. Mutable objects can be changed after they are created, while immutable objects can’t. We will simply list them here and learn more about them later in this chapter.,Lists and tuples are iterable in the obvious way: we step through it one element at a time starting at the beginning,In Python you often do not need to explicitly declare variables. The first usage of a variable acts to declare it. You can write:
$ python >>>
>>> exit() $
>>> if 1 > 2: ...print("oops!") ... else: ...print("This is what we expect") ... This is what we expect >>>
IndentationError: expected an indented block
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
!!/lectureNote/chapters / chapt03 / codes / examples / noIndentationForFortran.f90!! !!In this example, we show that there is no need to write a Fortran routine!!using proper indentations.Without indentations, it may look ugly but it!!still compiles and runs.!! program noIndentationForFortran implicit none integer, parameter::a = 1 if (a > 2) then print * , 'oops!' else print * , 'this is what we expect' end if end program noIndentationForFortran