Create README.md

Signed-off-by: David Rotermund <54365609+davrot@users.noreply.github.com>

python_basics/tuple/README.md

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+# Tuple
+{:.no_toc}
+
+<nav markdown="1" class="toc-class">
+* TOC
+{:toc}
+</nav>
+
+## The goal
+
+Tuple are a non-mutable container which is typically used for heterogenic data types and is very important for functions with multiple return values.
+
+Questions to [David Rotermund](mailto:davrot@uni-bremen.de)
+
+
+## [Tuples​](https://docs.python.org/3/library/stdtypes.html#tuple​)
+
+> Tuples are immutable sequences, typically used to store collections of heterogeneous data (such as the 2-tuples produced by the enumerate() built-in). Tuples are also used for cases where an immutable sequence of homogeneous data is needed (such as allowing storage in a set or dict instance).
+
+# Examples
+
+A tuple is a list of stuff that is enclosed in **( )** and seperated by **,** . An optional **,** after the last element is allowed. 
+
+```python
+a = (
+    "a",
+    "b",
+    "c",
+)
+print(a)
+
+a = ("a", "b", "c")
+print(a)
+```
+
+Output:
+
+```python
+('a', 'b', 'c')
+('a', 'b', 'c')
+```
+
+## Immutable
+
+After creating a tuple cannot be modified. They are immutable.
+
+```python
+a = (
+    "a",
+    "b",
+    "c",
+)
+
+a[0] = "d" # -> TypeError: 'tuple' object does not support item assignment
+```
+
+But this doesn't mean that we can not stored mutable objects in a tuple. Furthermore these mutable objects stay mutable. 
+
+```python
+a = (
+    ["a"],
+    "b",
+    "c",
+)
+
+a[0][0] = "d" # Okay, because changes the content of the list stored in a[0]
+a[0] = "d" # -> TypeError: 'tuple' object does not support item assignment
+```
+
+## Indexing
+
+Idexing is the same as in lists. 
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+)
+
+print(a[0]) # -> a
+print(a[1]) # -> 2
+print(a[-1]) # -> 3.3
+print(a[:1]) # -> ('a',)
+print(a[1:]) # -> (2, 3.3)
+print(a[::2]) # -> ('a', 3.3)
+```
+
+## *
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+)
+
+print(a*3)
+print(3*a)
+```
+
+Output:
+
+```python
+('a', 2, 3.3, 'a', 2, 3.3, 'a', 2, 3.3)
+('a', 2, 3.3, 'a', 2, 3.3, 'a', 2, 3.3)
+```
+
+## len()
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+)
+
+print(len(a)) # -> 3
+```
+
+## +
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+)
+
+b = (
+    "b",
+    8.8,
+    5,
+)
+
+print(a+b) # -> ('a', 2, 3.3, 'b', 8.8, 5)
+print(b+a) # -> ('b', 8.8, 5, 'a', 2, 3.3)
+```
+
+## in 
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+)
+
+
+print(2 in a) # -> True
+print(2 not in a) # -> False
+```
+
+## index()
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+)
+
+
+print(a.index(2)) # -> 1 
+print(a.index("a")) # -> 0
+```
+
+## count()
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+    "a",
+    2,
+    2,
+)
+
+
+print(a.count(2)) # -> 3
+print(a.count("a")) # -> 2 
+```
+
+## min() and max()
+
+```python
+a = (
+    9,
+    2,
+    3.3,
+    22,
+    2,
+    2,
+)
+
+print(min(a)) # -> 2
+print(max(a)) # -> 22
+```
+
+Strings are not allowed
+
+```python
+a = (
+    "a",
+    2,
+    3.3,
+    "a",
+    2,
+    2,
+)
+
+
+print(min(a))
+print(max(a))
+```
+
+Output:
+
+```python
+TypeError: '<' not supported between instances of 'int' and 'str'
+```
+
+## [Common Sequence Operations](https://docs.python.org/3/library/stdtypes.html#sequence-types-list-tuple-range​)
+
+
+|Operation​|Result​|
+|---|---|
+|x in s​|True if an item of s is equal to x, else False​|
+|x not in s​|False if an item of s is equal to x, else True​|
+|s + t​|the concatenation of s and t​|
+|s * n or n * s​|equivalent to adding s to itself n times​|
+|s[i]|​ith item of s, origin 0​|
+|s[i:j]|​slice of s from i to j​|
+|s[i:j:k]|​slice of s from i to j with step k​|
+|len(s)​|length of s​|
+|min(s)​|smallest item of s​|
+|max(s)​|largest item of s​|
+|s.index(x[, i[, j]])​|index of the first occurrence of x in s (at or after index i and before index j)​|
+|s.count(x)​|total number of occurrences of x in s​|
+