3.2. Sequence Tuple¶
3.2.1. Rationale¶
Can store elements of any types
Immutable - cannot add, modify or remove items
3.2.2. Type Definition¶
()is used more often
tuple()is more readableSingle element
tuplerequire comma at the end (important!)Brackets are optional
Comma after last element of one element tuple is optional
data = ()
data = tuple()
data = (1,)
data = 1,
data = (1, 2, 3)
data = (1.1, 2.2, 3.3)
data = (True, False)
data = ('a', 'b', 'c')
data = ('a', 1, 2.2, True, None)
data = 1, 2, 3
data = 1.1, 2.2, 3.3
data = True, False
data = 'a', 'b', 'c'
data = 'a', 1, 2.2, True, None
3.2.3. Type Casting¶
tuple()converts argument totuple
data = 'abcd'
tuple(data)
# ('a', 'b', 'c', 'd')
data = ['a', 'b', 'c', 'd']
tuple(data)
# ('a', 'b', 'c', 'd')
data = ('a', 'b', 'c', 'd')
tuple(data)
# ('a', 'b', 'c', 'd')
data = {1, 2, 3}
tuple(data)
# ('a', 'b', 'c', 'd')
data = frozenset({'a', 'b', 'c', 'd'})
tuple(data)
# ('a', 'b', 'c', 'd')
3.2.4. GetItem¶
More information in Sequence GetItem and Sequence Slice
data = ('a', 'b', 'c', 'd')
data[0] # 'a'
data[1] # 'b'
data[2] # 'c'
data[3] # 'd'
3.2.5. Tuple or Int, Float, Str¶
data = 1
type(data)
# <class 'int'>
data = 1,
type(data)
# <class 'tuple'>
data = 1.
type(data)
# <class 'float'>
type(1.2) # <class 'float'>
type(1,2) # <class 'tuple'>
type(1.2,) # <class 'tuple'>
type(1,2.3) # <class 'tuple'>
type(1.) # <class 'float'>
type(1,) # <class 'tuple'>
type(1.,) # <class 'tuple'>
type(.2) # <class 'float'>
type(.2,) # <class 'tuple'>
type(1.2) # <class 'float'>
type(1) # <class 'int'>
type(1.,1.) # <class 'tuple'>
type(.2,.2) # <class 'tuple'>
type(1.,.2) # <class 'tuple'>
type('foo') # <class 'str'>
type('foo',) # <class 'tuple'>
type('foo'.) # SyntaxError: invalid syntax
3.2.6. Tuple or List¶
Both:
ordered
possible to getitem and slice
elements can be duplicated
elements of any types
Tuple:
immutable
one contingent block of data in memory
List:
mutable
implemented in memory as list of pointers to objects
objects are scattered in memory
from sys import getsizeof
a = [1, 2, 3]
b = (1, 2, 3)
getsizeof(a)
# 120
getsizeof(b)
# 64
Figure 3.1. Define tuple¶
Figure 3.2. Define list¶
Figure 3.3. Define str, tuple and list¶
3.2.7. Assignments¶
"""
* Assignment: Sequence Tuple Create
* Filename: sequence_tuple_create.py
* Complexity: easy
* Lines of code to write: 1 lines
* Estimated time: 2 min
English:
1. Create tuple `result` with elements:
a. `'a'`
b. `1`
c. `2.2`
2. Compare result with "Tests" section (see below)
Polish:
1. Stwórz tuple `result` z elementami:
a. `'a'`
b. `1`
c. `2.2`
2. Porównaj wyniki z sekcją "Tests" (patrz poniżej)
Tests:
>>> type(result)
<class 'tuple'>
>>> len(result)
3
>>> 'a' in result
True
>>> 1 in result
True
>>> 2.2 in result
True
"""
"""
* Assignment: Sequence Tuple Select
* Filename: sequence_tuple_select.py
* Complexity: easy
* Lines of code to write: 1 lines
* Estimated time: 5 min
English:
1. Use data from "Given" section (see below)
2. Create a `tuple` representing all species
3. To convert table use multiline select with `alt` key in your IDE
4. Do not use `slice`, `getitem`, `for`, `while` or any other control-flow statement
5. Compare result with "Tests" section (see below)
Polish:
1. Użyj danych z sekcji "Given" (patrz poniżej)
2. Stwórz `tuple` z nazwami gatunków
3. Do konwersji tabelki wykorzystaj zaznaczanie wielu linijek za pomocą klawisza `alt` w Twoim IDE
4. Nie używaj `slice`, `getitem`, `for`, `while` lub jakiejkolwiek innej instrukcji sterującej
5. Porównaj wyniki z sekcją "Tests" (patrz poniżej)
Hints:
* `ALT` + `left mouse button` = multiple select
* `ALT` + `SHIFT` + `left mouse button drag` = vertical selection
Tests:
>>> type(result)
<class 'tuple'>
>>> all(type(x) is str for x in result)
True
>>> ('sepal_length' not in result
... and 'sepal_width' not in result
... and 'petal_length' not in result
... and 'petal_width' not in result
... and 'species' not in result)
True
>>> len(result)
5
>>> result.count('virginica')
2
>>> result.count('setosa')
1
>>> result.count('versicolor')
2
"""
# Given
DATA = ['sepal_length,sepal_width,petal_length,petal_width,species',
'5.8,2.7,5.1,1.9,virginica',
'5.1,3.5,1.4,0.2,setosa',
'5.7,2.8,4.1,1.3,versicolor',
'6.3,2.9,5.6,1.8,virginica',
'6.4,3.2,4.5,1.5,versicolor']
"""
* Assignment: Sequence Tuple Mean
* Filename: sequence_tuple_mean.py
* Complexity: medium
* Lines of code to write: 8 lines
* Estimated time: 8 min
English:
1. Use data from "Given" section (see below)
2. Calculate mean for each numerical values column
3. To convert table use multiline select with `alt` key in your IDE
7. Do not use `str.split()`, `slice`, `getitem`, `for`, `while` or any other control-flow statement
5. Compare result with "Tests" section (see below)
Polish:
1. Użyj danych z sekcji "Given" (patrz poniżej)
2. Wylicz średnią arytmetyczną dla każdej z kolumn numerycznych
3. Do konwersji tabelki wykorzystaj zaznaczanie wielu linijek za pomocą klawisza `alt` w Twoim IDE
4. Nie używaj `str.split()`, `slice`, `getitem`, `for`, `while` lub jakiejkolwiek innej instrukcji sterującej
5. Porównaj wyniki z sekcją "Tests" (patrz poniżej)
Hints:
* `mean = sum(...) / len(...)`
* `ALT` + `left mouse button` = multiple select
* `ALT` + `SHIFT` + `left mouse button drag` = vertical selection
* `ALT` + `SHIFT` + `right` = select word to the right (macOS)
* `ALT` + `SHIFT` + `left` = select word to the left (macOS)
* `CTRL` + `SHIFT` + `right` = select word to the right (Windows)
* `CTRL` + `SHIFT` + `left` = select word to the left (Windows)
* `CTRL` + `right` = jump over the word to the right
* `CTRL` + `left` = jump over the word to the left
* `CTRL` + `ALT` + L = Reformat Code on Windows
* `CMD` + `ALT` + L = Reformat Code on macOS
Tests:
>>> type(sepal_length)
<class 'float'>
>>> type(sepal_width)
<class 'float'>
>>> type(petal_length)
<class 'float'>
>>> type(petal_width)
<class 'float'>
>>> sepal_length
5.859999999999999
>>> sepal_width
3.0200000000000005
>>> petal_length
4.14
>>> petal_width
1.34
"""
# Given
DATA = ['sepal_length,sepal_width,petal_length,petal_width,species',
'5.8,2.7,5.1,1.9,virginica',
'5.1,3.5,1.4,0.2,setosa',
'5.7,2.8,4.1,1.3,versicolor',
'6.3,2.9,5.6,1.8,virginica',
'6.4,3.2,4.5,1.5,versicolor']