# Python – Extract digits from Tuple list

Sometimes, while working with Python lists, we can have a problem in which we need to perform extraction of all the digits from tuple list. This kind of problem can find its application in data domains and day-day programming. Let’s discuss certain ways in which this task can be performed.

Input: test_list = [(15, 3), (3, 9)]Output: [9, 5, 3, 1]

Input: test_list = [(15, 3)]Output: [5, 3, 1]

**Method #1: Using map() + chain.from_iterable() + set() + loop**

The combination of above functions can be used to solve this problem. In this, we perform the task of flattening list using chain.from_iterable(), and then the digits are extracted using brute method. set() is used to remove duplicate digits.

## Python3

`# Python3 code to demonstrate working of` `# Extract digits from Tuple list` `# Using map() + chain.from_iterable() + set() + loop` `from` `itertools ` `import` `chain` `# initializing list` `test_list ` `=` `[(` `15` `, ` `3` `), (` `3` `, ` `9` `), (` `1` `, ` `10` `), (` `99` `, ` `2` `)]` `# printing original list` `print` `(` `"The original list is : "` `+` `str` `(test_list))` `# Extract digits from Tuple list` `# Using map() + chain.from_iterable() + set() + loop` `temp ` `=` `map` `(` `lambda` `ele: ` `str` `(ele), chain.from_iterable(test_list))` `res ` `=` `set` `()` `for` `sub ` `in` `temp:` ` ` `for` `ele ` `in` `sub:` ` ` `res.add(ele)` `# printing result` `print` `(` `"The extracted digits : "` `+` `str` `(res))` |

**Output**

The original list is : [(15, 3), (3, 9), (1, 10), (99, 2)] The extracted digits : {'1', '0', '3', '2', '9', '5'}

**Method #2: Using regex expression**

This is yet another way in which this task can be performed. In this, an appropriate regex expression is used to extract the required unique digits.

## Python3

`# Python3 code to demonstrate working of` `# Extract digits from Tuple list` `# Using regex expression` `import` `re` `# initializing list` `test_list ` `=` `[(` `15` `, ` `3` `), (` `3` `, ` `9` `), (` `1` `, ` `10` `), (` `99` `, ` `2` `)]` `# printing original list` `print` `(` `"The original list is : "` `+` `str` `(test_list))` `# Extract digits from Tuple list` `# Using regex expression` `temp ` `=` `re.sub(r` `'[\[\]\(\), ]'` `, '', ` `str` `(test_list))` `res ` `=` `[` `int` `(ele) ` `for` `ele ` `in` `set` `(temp)]` `# printing result` `print` `(` `"The extracted digits : "` `+` `str` `(res))` |

**Output**

The original list is : [(15, 3), (3, 9), (1, 10), (99, 2)] The extracted digits : [5, 9, 2, 0, 1, 3]

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