Python: How to write data in file in specific format?

Question

i have an array called MAC1_Val:

MAC1_Val array([ 1.00000000e+00, -1.00000000e+01, -2.06306600e+02, 2.22635749e+02, 1.00000000e+00, 1.00000000e+01, 1.00000000e+01, -2.06306600e+02, 2.22635749e+02, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 0.00000000e+00, 1.00000000e+00, -1.08892735e+01, 1.88607749e+01, 1.03153300e+01, -1.78666757e+01, 3.33333333e-07, -3.33333333e-07, -4.21637021e-05, 4.21637021e-05, 9.98844400e-01, -1.73973001e-03, 1.20938900e-03, 1.87742948e-03, -3.33333333e-03, 6.66666667e-03, -3.33333333e-03, -2.64911064e-01, -2.60959501e+01, 2.81614422e+01, 3.33333333e-03, -6.66666667e-03, 3.33333333e-03, 0.00000000e+00, 0.00000000e+00])

and i want to write in file (.txt) values in specific format like this:

1.000000e+00
-1.000000e+01 
-2.063066e+02
2.226357e+02
1.000000e+00   
1.000000e+01 .......

note that are 6 digits behind floating point

any suggestions how to do this? thanks in advance!

Answer 1

Use string interpolation to format the number.

'%.3f' % (1.23456,)

Answer 2

printf standard is your friend:

for i in MAC1_Val:
    print "%.6e" % i

1.000000e+00
-1.000000e+01
-2.063066e+02
2.226357e+02
1.000000e+00
1.000000e+01
1.000000e+01