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Given the following text description, write Python code to implement the functionality described.
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Description:
Equilibrium index of an array
Python program to find the equilibrium index of an array Function to find the equilibrium index ; Iterate from 0 to len ( arr ) ; If i is not 0 ; Iterate from 0 to len ( arr ) ; If no equilibrium index found , then return - 1 ; Driver code

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Python Code:
def equilibrium(arr ) : 
	 left_sum =[] 
 right_sum =[] 
 for i in range(len(arr ) ) : 
	 if(i ) : 
	 left_sum . append(left_sum[i - 1 ] + arr[i ] ) 
 right_sum . append(right_sum[i - 1 ] + arr[len(arr ) - 1 - i ] ) 
  else : 
	 left_sum . append(arr[i ] ) 
 right_sum . append(arr[len(arr ) - 1 ] ) 
   for i in range(len(arr ) ) : 
	 if(left_sum[i ] == right_sum[len(arr ) - 1 - i ] ) : 
	 return(i ) 
   return - 1 
  arr =[- 7 , 1 , 5 , 2 , - 4 , 3 , 0 ] 
 print(' First ▁ equilibrium ▁ index ▁ is ▁ ' , equilibrium(arr ) ) 

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