Question

I have a txt file that I read with:

fdata =[]
with open(fn,'rb') as fo:
     for i in xrange(1):
           fo.next()
     for line in fo:                       
           data = line.split(',')
           data = data[:23]
           fdata.append(data)    
     print fdata 

I would like convert the entire table to numbers from string. AND limit the table size to read to XXX lines.

Answer 1

To limit lines, try iterating using a counter and readlines():

maxlines = 100
lines = f.readlines()

if maxlines > len(lines):  maxlines = len(lines)

for i in xrange(maxlines):
  line = lines[i]

  # Do your stuff...

To convert a string to a number (an integer in this case. float() is for floating points):

print '9000' == 9000 # False.
print int('9000') == 9000 # True

So to make your table only include integers, convert each line (after splitting) into an integer. int() only returns an integer, so it doesn’t modify your variable. Replacing fdata.append(data)) with fdata.append(int(data() should do the trick.

---

Okay, to convert your entire list into integers, just iterate over each of those 23 elements to convert them into integers. This works for an arbitrary list of strings:

for element in data:
  element = int(element)

---

To convert your list into integers, but to exclude your first element, loop through it:

for i in xrange(1, len(data)): # I used 1 because 0 is the first element. This skips it.
  data[i] = int(data[i])