"""
given a list of returns, returns the maximum drawdown of the returns

drawdown is calculated by taking the highest cumulative return so far, and calculating the difference of the current cumulative return from 
the peak

the minimum  of the drawdowns is max drawdown
"""

def max_dd(returns_list):
    #returns are in the form of % ex: 1.5%, 2% etc. without the % sign
    cumulative_returns=[]
    drawdown=[]
    cum_ret=0
    for i in returns_list:
        cum_ret=cum_ret+i
        cumulative_returns.append(cum_ret)
        dd=cum_ret-max(cumulative_returns)
      
        drawdown.append(dd)
    return cumulative_returns,min(drawdown)

if __name__=='__main__':
    test_dd=max_dd([1.1,1.1,-2,-7,25,34,-4,-3,-3,-5,1.2,-6])
    print(test_dd)