# Python Program to Find Most common elements set

Given a List of sets, the task is to write a Python program tocompare elements with argument set, and return one with maximum matching elements.

**Examples:**

Input :test_list = [{4, 3, 5, 2}, {8, 4, 7, 2}, {1, 2, 3, 4}, {9, 5, 3, 7}], arg_set = {9, 6, 5, 3}

Output :{9, 3, 5, 7}

Explanation :Resultant set has maximum matching elements.

Input :test_list = [{4, 3, 5, 2}, {8, 4, 7, 2}, {1, 2, 3, 4}, {9, 5, 3, 7}], arg_set = {4, 6, 5, 3}

Output :{2, 3, 4, 5}

Explanation :Resultant set has maximum matching elements.

**Method 1: Using ****loop ****+ ****set.intersection()**

In this, we perform task of getting all the common elements with argument set using intersection(), and get its length using len(), and maximum length and set is compared and updated during iteration.

## Python3

`# Python3 code to demonstrate working of` `# Most common elements set` `# Using loop + intersection()` ` ` `# initializing list` `test_list ` `=` `[{` `4` `, ` `3` `, ` `5` `, ` `2` `}, {` `8` `, ` `4` `, ` `7` `, ` `2` `},` ` ` `{` `1` `, ` `2` `, ` `3` `, ` `4` `}, {` `9` `, ` `5` `, ` `3` `, ` `7` `}]` ` ` `# printing original list` `print` `(` `"The original list is : "` `+` `str` `(test_list))` ` ` `# initializing arg_set` `arg_set ` `=` `{` `9` `, ` `6` `, ` `5` `, ` `3` `}` ` ` `res ` `=` `set` `()` `max_len ` `=` `0` ` ` `for` `sub ` `in` `test_list:` ` ` ` ` `# updating max value on occurrence` ` ` `if` `len` `(sub.intersection(arg_set)) > max_len:` ` ` `max_len ` `=` `len` `(sub.intersection(arg_set))` ` ` `res ` `=` `sub` ` ` `# printing result` `print` `(` `"Max Set intersection : "` `+` `str` `(res))` |

**Output:**

The original list is : [{2, 3, 4, 5}, {8, 2, 4, 7}, {1, 2, 3, 4}, {9, 3, 5, 7}] Max Set intersection : {9, 3, 5, 7}

**Method 2 : Using**** max()**** +**** list comprehension**** +**** intersection()**

In this, initial step is to check for the lengths of all intersected set results and get maximum using max(). Next, task of getting set which matches required length is extracted.

## Python3

`# Python3 code to demonstrate working of` `# Most common elements set` `# Using loop + intersection()` ` ` `# initializing list` `test_list ` `=` `[{` `4` `, ` `3` `, ` `5` `, ` `2` `}, {` `8` `, ` `4` `, ` `7` `, ` `2` `},` ` ` `{` `1` `, ` `2` `, ` `3` `, ` `4` `}, {` `9` `, ` `5` `, ` `3` `, ` `7` `}]` ` ` `# printing original list` `print` `(` `"The original list is : "` `+` `str` `(test_list))` ` ` `# initializing arg_set` `arg_set ` `=` `{` `9` `, ` `6` `, ` `5` `, ` `3` `}` ` ` `# getting maximum length ` `max_len ` `=` `max` `(` `len` `(sub.intersection(arg_set)) ` `for` `sub ` `in` `test_list)` ` ` `# getting element matching length` `res ` `=` `[sub ` `for` `sub ` `in` `test_list ` `if` `len` `(sub.intersection(arg_set)) ` `=` `=` `max_len][` `0` `]` ` ` `# printing result` `print` `(` `"Set intersection : "` `+` `str` `(res))` |

**Output:**

The original list is : [{2, 3, 4, 5}, {8, 2, 4, 7}, {1, 2, 3, 4}, {9, 3, 5, 7}] Max Set intersection : {9, 3, 5, 7}

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