How to read multiple text files into arrays?

Question

I have multiple text files, each containing several columns. I need to read each file into an array in python, called RDF. The point is that I used to read one file into one array as following:

RDF_1 = numpy.loadtxt("filename_1.txt", skiprows=205, usecols=(1,), unpak=True)

How to create a loop in python such that it reads more than one file into their corresponding arrays like this:

for i in range(100):
    RDF_i =  numpy.loadtxt("filename_"+str(i)+".txt", skiprows=205, usecols=(1,), unpak=True)

This is a really bad way to code - your variable names should not be created dynamically — Alan Kavanagh
– Alan Kavanagh, Commented Feb 2, 2020 at 20:17
Can you provide a higher level context to what you are trying to achieve? I don't think you need to store the results of numpy.loadtxt inside a variable each time -- you are risking reading a lot of information into memory — Alan Kavanagh
– Alan Kavanagh, Commented Feb 2, 2020 at 20:19
Does this answer your question? How do I create a variable number of variables? — alkasm
– alkasm, Commented Feb 2, 2020 at 20:50

Charnel · Accepted Answer · 2020-02-02 20:20:29Z

1

You can use dictionaries as a proper way:

files_mapping = dict()
for i in range(100):
    files_mapping[f'RDF_{i}'] = numpy.loadtxt(f"filename_{i}.txt", skiprows=205, usecols=(1,), unpak=True)

But if for some unknown reasons you really need to dynamically create variables then you can use exec:

for i in range(100):
    exac(f'RDF_{i} = numpy.loadtxt(f"filename_{i}.txt", skiprows=205, usecols=(1,), unpak=True)'

And another possible way is using locals:

for i in range(100):
    locals()[f'RDF_{i}'] = numpy.loadtxt(f"filename_{i}.txt", skiprows=205, usecols=(1,), unpak=True)

You need to avoid using two last options in real code because it's a direct way to spawning hard-to-find bugs.

answered Feb 2, 2020 at 20:20

Charnel

4,4422 gold badges18 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Mohammed Alhissi · Accepted Answer · 2020-02-09 17:38:19Z

0

I found a way to do it. I use two dimensional arrys after importing numpy library.

However, I had to zero the arrays before filling them out with data because python had already filled them out with random values.

answered Feb 9, 2020 at 17:38

Mohammed Alhissi

896 bronze badges

Collectives™ on Stack Overflow

How to read multiple text files into arrays?

2 Answers 2

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related