I have a big list of lists like this in Python 3:
array = [[262,231],[123,222],[237272,292]...]
I want to save this in binary in python I tried this:
output = open("pratica3.dat", "wb")
inbytes = bytes(array)
output.write(inbytes)
But this gives an error:
TypeError: 'list' object cannot be interpreted as an integer
And if I try to run through the list and save, this gives me annother error of out of range 256
I think you're looking for pickle:
import pickle
pickle.dump(array, output) # converts array to binary and writes to output
array = pickle.load(output) # Reads the binary and converts back to list
To save the array as binary file, you need to open a binary file using open(filename, 'wb'). Otherwise, only using pickle.dump() throws TypeError: file must have 'write' attribute.
So, the code looks like this.
import pickle as pk
#save as binary file
pk.dump(your_array, open(filename, 'wb'))
Try with pickle it will work fine
import pickle # import pickle
fptr = open("filename", "wb") # open file in write binary mode
pickle.dump(my_list, ftpt) # dump list data into file
fptr.close() # close file pointer
fptr = open("filename", "rb") # open file in read binary mode
test_list = pickle.load(fptr) # read binary data from file and store in list
print(test_list) # print the data
fptr.close()
bytesdoesn't work on arbitrary data structures. Trypickle.json?pickle? Is there any specific format? e.g. the array contains sublists of length 2 that only hold integers? In that case, you can probably get the most minimal file size usingnumpy.