In python, how do I print a table using double for loops? -

here python code,

from fractions import gcd  print "| 2 3 4 5 6 7 8 9 10 11 12 13 14 15" print "-----------------------------------" xlist = range(2,16) ylist = range(2,51) b in ylist:      print b, " | "      in xlist:         print gcd(a,b) 

i'm having trouble printing table display on top row 2-15 , on left column values 2-50. gcd table each value each row , each column.

here sample of i'm getting

| 2 3 4 5 6 7 8 9 10 11 12 13 14 15

---

2 |

2

1

2

you can have more concise list comprehension:

from fractions import gcd print("   |   2  3  4  5  6  7  8  9 10 11 12 13 14 15") print("-----------------------------------------------") xlist = range(2,16) ylist = range(2,51)  print("\n".join(" ".join(["%2d | " % b] + [("%2d" % gcd(a, b)) in xlist]) b in ylist)) 

output:

   |   2  3  4  5  6  7  8  9 10 11 12 13 14 15 -----------------------------------------------  2 |   2  1  2  1  2  1  2  1  2  1  2  1  2  1  3 |   1  3  1  1  3  1  1  3  1  1  3  1  1  3  4 |   2  1  4  1  2  1  4  1  2  1  4  1  2  1  5 |   1  1  1  5  1  1  1  1  5  1  1  1  1  5  6 |   2  3  2  1  6  1  2  3  2  1  6  1  2  3  7 |   1  1  1  1  1  7  1  1  1  1  1  1  7  1  8 |   2  1  4  1  2  1  8  1  2  1  4  1  2  1  9 |   1  3  1  1  3  1  1  9  1  1  3  1  1  3 10 |   2  1  2  5  2  1  2  1 10  1  2  1  2  5 11 |   1  1  1  1  1  1  1  1  1 11  1  1  1  1 12 |   2  3  4  1  6  1  4  3  2  1 12  1  2  3 13 |   1  1  1  1  1  1  1  1  1  1  1 13  1  1 14 |   2  1  2  1  2  7  2  1  2  1  2  1 14  1 15 |   1  3  1  5  3  1  1  3  5  1  3  1  1 15 16 |   2  1  4  1  2  1  8  1  2  1  4  1  2  1 17 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 18 |   2  3  2  1  6  1  2  9  2  1  6  1  2  3 19 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 20 |   2  1  4  5  2  1  4  1 10  1  4  1  2  5 21 |   1  3  1  1  3  7  1  3  1  1  3  1  7  3 22 |   2  1  2  1  2  1  2  1  2 11  2  1  2  1 23 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 24 |   2  3  4  1  6  1  8  3  2  1 12  1  2  3 25 |   1  1  1  5  1  1  1  1  5  1  1  1  1  5 26 |   2  1  2  1  2  1  2  1  2  1  2 13  2  1 27 |   1  3  1  1  3  1  1  9  1  1  3  1  1  3 28 |   2  1  4  1  2  7  4  1  2  1  4  1 14  1 29 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 30 |   2  3  2  5  6  1  2  3 10  1  6  1  2 15 31 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 32 |   2  1  4  1  2  1  8  1  2  1  4  1  2  1 33 |   1  3  1  1  3  1  1  3  1 11  3  1  1  3 34 |   2  1  2  1  2  1  2  1  2  1  2  1  2  1 35 |   1  1  1  5  1  7  1  1  5  1  1  1  7  5 36 |   2  3  4  1  6  1  4  9  2  1 12  1  2  3 37 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 38 |   2  1  2  1  2  1  2  1  2  1  2  1  2  1 39 |   1  3  1  1  3  1  1  3  1  1  3 13  1  3 40 |   2  1  4  5  2  1  8  1 10  1  4  1  2  5 41 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 42 |   2  3  2  1  6  7  2  3  2  1  6  1 14  3 43 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 44 |   2  1  4  1  2  1  4  1  2 11  4  1  2  1 45 |   1  3  1  5  3  1  1  9  5  1  3  1  1 15 46 |   2  1  2  1  2  1  2  1  2  1  2  1  2  1 47 |   1  1  1  1  1  1  1  1  1  1  1  1  1  1 48 |   2  3  4  1  6  1  8  3  2  1 12  1  2  3 49 |   1  1  1  1  1  7  1  1  1  1  1  1  7  1 50 |   2  1  2  5  2  1  2  1 10  1  2  1  2  5 

this works in python2 and python3. if want zeros @ beginning of each one-digit number, replace each occurence of %2d %02d. shouldn't print header that, more this:

from fractions import gcd xlist = range(2, 16) ylist = range(2, 51) string = "   | " + " ".join(("%2d" % x) x in xlist) print(string) print("-" * len(string))  print("\n".join(" ".join(["%2d | " % b] + [("%2d" % gcd(a, b)) in xlist]) b in ylist)) 

this way, if change xlist or ylist, table still good.