You can use while loop to successively increment value of a variable i by one and adding it cumulatively.
s,i=0,0 n=10 while i<n: i=i+1 s=s+i print ("sum of first 10 natural numbers",s)
For loop is also used to loop over a range of natural numbers and add them cumulatively.
s=0 for i in range(11): s=s+i print ("sum of first 10 natural numbers",s)
Lastly using the built in function sum() also gives sum of a range of numbers
s=sum(range(11)) print ("sum of first 10 natural numbers",s)