# Differences and Applications of List, Tuple, Set and Dictionary in Python

** Lists:** are just like dynamic sized arrays, declared in other languages (vector in C++ and ArrayList in Java). Lists need not be homogeneous always which makes it a most powerful tool in Python.

** Tuple:** A Tuple is a collection of Python objects separated by commas. In someways a tuple is similar to a list in terms of indexing, nested objects and repetition but a tuple is immutable unlike lists that are mutable.

** Set:** A Set is an unordered collection data type that is iterable, mutable and has no duplicate elements. Python’s set class represents the mathematical notion of a set.

__Dictionary:__** **in Python is an unordered collection of data values, used to store data values like a map, which unlike other Data Types that hold only single value as an element, Dictionary holds **key:value** pair. Key value is provided in the dictionary to make it more optimized.

List, Tuple, Set, and Dictionary are the data structures in python that are used to store and organize the data in an efficient manner.

List | Tuple | Set | Dictionary |

List is a non-homogeneous data structure which stores the elements in single row and multiple rows and columns | Tuple is also a non-homogeneous data structure which stores single row and multiple rows and columns | Set data structure is also non-homogeneous data structure but stores in single row | Dictionary is also a non-homogeneous data structure which stores key value pairs |

List can be represented by [ ] | Tuple can be represented by ( ) | Set can be represented by { } | Dictionary can be represented by { } |

List allows duplicate elements | Tuple allows duplicate elements | Set will not allow duplicate elements | Set will not allow duplicate elements but keys are not duplicated |

List can use nested among all | Tuple can use nested among all | Set can use nested among all | Dictionary can use nested among all |

Example: [1, 2, 3, 4, 5] | Example: (1, 2, 3, 4, 5) | Example: {1, 2, 3, 4, 5} | Example: {1, 2, 3, 4, 5} |

List can be created using list() function | Tuple can be created using tuple() function. | Set can be created using set() function | Dictionary can be created using dict() function. |

List is mutable i.e we can make any changes in list. | Tuple is immutable i.e we can not make any changes in tuple | Set is mutable i.e we can make any changes in set. But elements are not duplicated. | Dictionary is mutable. But Keys are not duplicated. |

List is ordered | Tuple is ordered | Set is unordered | Dictionary is ordered |

Creating an empty list l=[] | Creating an empty Tuple t=() | Creating a set a=set() b=set(a) | Creating an empty dictionary d={} |

Below is the program for implementation of List, tuple, set, and dictionary:

## Python3

`# Python3 program for explaining` `# use of list, tuple, set and` `# dictionary` `# Lists` `l ` `=` `[]` `# Adding Element into list` `l.append(` `5` `)` `l.append(` `10` `)` `print` `(` `"Adding 5 and 10 in list"` `, l)` `# Popping Elements from list` `l.pop()` `print` `(` `"Popped one element from list"` `, l)` `print` `()` `# Set` `s ` `=` `set` `()` `# Adding element into set` `s.add(` `5` `)` `s.add(` `10` `)` `print` `(` `"Adding 5 and 10 in set"` `, s)` `# Removing element from set` `s.remove(` `5` `)` `print` `(` `"Removing 5 from set"` `, s)` `print` `()` `# Tuple` `t ` `=` `tuple` `(l)` `# Tuples are immutable` `print` `(` `"Tuple"` `, t)` `print` `()` `# Dictionary` `d ` `=` `{}` `# Adding the key value pair` `d[` `5` `] ` `=` `"Five"` `d[` `10` `] ` `=` `"Ten"` `print` `(` `"Dictionary"` `, d)` `# Removing key-value pair` `del` `d[` `10` `]` `print` `(` `"Dictionary"` `, d)` |

**Output**

Adding 5 and 10 in list [5, 10] Popped one element from list [5] Adding 5 and 10 in set {10, 5} Removing 5 from set {10} Tuple (5,) Dictionary {5: 'Five', 10: 'Ten'} Dictionary {5: 'Five'}

### Applications of List, Set, Tuple, and Dictionary

**List:**

- Used in JSON format
- Useful for Array operations
- Used in Databases

**Tuple:**

- Used to insert records in the database through SQL query at a time

Ex: (1.’sravan’, 34).(2.’geek’, 35)

- Used in parentheses checker

**Set**

- Finding unique elements
- Join operations

**Dictionary**

- Used to create a data frame with lists
- Used in JSON

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