Given a list of tuples, the task is to convert it into list of all digits which exists in elements of list.

Let’s discuss certain ways in which this task is performed.

**Method #1: Using re**

The most concise and readable way to convert list of tuple into list of all digits which exists in elements of list is by using *re*.

`# Python code to convert list of tuples into` `# list of all digits which exists` `# in elements of list.` ` ` `# Importing` `import` `re` ` ` `# Input list initialization` `lst ` `=` `[(` `11` `, ` `100` `), (` `22` `, ` `200` `), (` `33` `, ` `300` `), (` `44` `, ` `400` `), (` `88` `, ` `800` `)]` ` ` `# Using re` `temp ` `=` `re.sub(r` `'[\[\]\(\), ]'` `, '', ` `str` `(lst))` ` ` `# Using set` `Output ` `=` `[` `int` `(i) ` `for` `i ` `in` `set` `(temp)]` ` ` `# Printing output` `print` `(` `"Initial List is :"` `, lst)` `print` `(` `"Output list is :"` `, Output)` |

**Output:**

Initial List is : [(11, 100), (22, 200), (33, 300), (44, 400), (88, 800)]

Output list is : [1, 4, 8, 0, 3, 2]

**Method #2: Using itertools.chain() and lambda()**

This is yet another way to perform this particular task using `lambda()`

.

`# Python code to convert list of tuples into` `# list of all digits which exists` `# in elements of list.` ` ` `# Importing` `from` `itertools ` `import` `chain` ` ` `# Input list initialization` `lst ` `=` `[(` `11` `, ` `100` `), (` `22` `, ` `200` `), (` `33` `, ` `300` `), (` `44` `, ` `400` `), (` `88` `, ` `800` `)]` ` ` `# using lambda` `temp ` `=` `map` `(` `lambda` `x: ` `str` `(x), chain.from_iterable(lst))` ` ` `# Output list initialization` `Output ` `=` `set` `()` ` ` `# Adding element in Output` `for` `x ` `in` `temp:` ` ` `for` `elem ` `in` `x:` ` ` `Output.add(elem)` ` ` `# Printing output` `print` `(` `"Initial List is :"` `, lst)` `print` `(` `"Output list is :"` `, Output)` |

**Output:**

Initial List is : [(11, 100), (22, 200), (33, 300), (44, 400), (88, 800)]

Output list is : {‘8’, ‘4’, ‘0’, ‘2’, ‘1’, ‘3’}

Attention geek! Strengthen your foundations with the **Python Programming Foundation** Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the **Python DS** Course. And to begin with your Machine Learning Journey, join the **Machine Learning – Basic Level Course**