CODEWITHSUNDEEP
pythonnumpy
Håkon Hægland
Håkon Hægland

Reputation: 40718

Saving numpy arrays as part of a larger text file

How can I save NumPy arrays as part of a larger text file? I can write the arrays to a temp file using savetxt, and then read them back into a string, but this seems like redundant and inefficient coding (some of the arrays will be large). For example:

from numpy import *

a=reshape(arange(12),(3,4))
b=reshape(arange(30),(6,5))

with open ('d.txt','w') as fh:
    fh.write('Some text\n')
    savetxt('tmp.txt', a, delimiter=',')
    with open ("tmp.txt", "r") as th:
        str=th.read()
    fh.write(str)
    fh.write('Some other text\n')
    savetxt('tmp.txt', b, delimiter=',')
    with open ("tmp.txt", "r") as th:
        str=th.read()
    fh.write(str)

Upvotes: 0

Views: 79

Answers (1)

RomanHotsiy
RomanHotsiy

Reputation: 5138

First parameter of savetxt

fname : filename or file handle

So, you can open file in append mode and write to it:

with open ('d.txt','a') as fh:
  fh.write('Some text\n')
  savetxt(fh, a, delimiter=',')
  fh.write('Some other text\n')
  savetxt(fh, b, delimiter=',')

Upvotes: 2

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