For a simple file (file.txt)…
colA,colB 324,234 346,341 147,346 234,567 368,405 344,643 235,235 236,567
Method 1: Open the whole file as one big string.
f = open('file.txt', 'r') # 'r' = read lines = f.read() print lines, f.close()
Alternatively, file can be read into a numpy array for easy plotting
import numpy as np f = open('file.txt', 'r') data = np.genfromtxt(f, delimiter=',') delete(data,0,0) # Erases the first row (i.e. the header) plot(data[:,0],data[:,1],'o') f.close()
Method 2: Open the whole file at once as a list of lines (i.e. each element in list = one line of the file).
f = open('file.txt', 'r') # 'r' = read lines = f.readlines() print lines, f.close()
Method 3: Open a file “line-by-line”. This method doesn’t use a lot of memory (one line’s worth of memory at any given time), so it is good for really large files.
f = open('file.txt', 'r') # 'r' = read for line in f: print line, # note, coma erases the "cartridge return" f.close()