Why does this Python program run 3x faster than an identical Julia program -

i wanted try julia programming language, heard supposed faster python. decided try dynamic program project euler #14, dealt lot of computation (finding longest collatz sequence).

i wrote program in julia, , decided try make analogous program in python, see how fast each of them were. however, on machine, python program runs in 2 seconds, while julia 1 takes 7. surprised me, because said before julia claims faster python, wondering if there inherent scripts makes julia 1 slower. attempted have them both computed in same way.

here scripts, appreciate insight!

julia:

global max_val = 0 global max_item = 0 global d = dict{integer,integer}() function coll_length(n)     #println(n)     global max_val     global max_item     global d     if haskey(d,n)         return d[n]     end     if n==1         answer = 1     elseif n%2==1         answer = 1+coll_length(3n+1)     else         answer = 1+coll_length(n/2)     end      d[n]=answer     if max_val<answer         max_val=answer         max_item=n     end     return answer end   = 1:1000000     coll_length(i) end println(max_item) 

python:

d = {} max_val = 0 max_item = 0  def coll_length(n):     global d      global max_val      global max_item       if n in d:         return d[n]     if n==1:         answer= 1     elif n%2==0:         answer= 1+coll_length(n/2)     else:         answer= 1+coll_length(3*n+1)      d[n]=answer     if max_val<answer:         max_val=answer         max_item=n     return answer  n in range(1,1000000+1):     coll_length(n) print max_item