# Lambda expression in Python to rearrange positive and negative numbers

Given an array of positive and negative numbers, arrange them such that all negative integers appear before all the positive integers in the array. The order of appearance should be maintained.

Examples:

Input : arr[] = [12, 11, -13, -5, 6, -7, 5, -3, -6] Output : arr[] = [-13, -5, -7, -3, -6, 12, 11, 6, 5] Input : arr[] = [-12, 11, 0, -5, 6, -7, 5, -3, -6] Output : arr[] = [-12, -5, -7, -3, -6, 11, 0, 6, 5]

This problem has many solutions please refer Rearrange positive and negative numbers link, but we will solve this problem with single line of code in python using Lambda Expression.

`# Function to rearrange positive and negative elements` `def` `Rearrange(arr):` ` ` ` ` `# First lambda expression returns list of negative numbers` ` ` `# in arr.` ` ` `# Second lambda expression returns list of positive numbers` ` ` `# in arr.` ` ` `return` `[x ` `for` `x ` `in` `arr ` `if` `x < ` `0` `] ` `+` `[x ` `for` `x ` `in` `arr ` `if` `x >` `=` `0` `]` ` ` `# Driver function` `if` `__name__ ` `=` `=` `"__main__"` `:` ` ` `arr ` `=` `[` `12` `, ` `11` `, ` `-` `13` `, ` `-` `5` `, ` `6` `, ` `-` `7` `, ` `5` `, ` `-` `3` `, ` `-` `6` `]` ` ` `print` `(Rearrange(arr))` |

Output:

arr[] = [-13, -5, -7, -3, -6, 12, 11, 6, 5]

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