Python — How do you view output that doesn't fit the screen?

Question

I should say I\'m looking for a solution to the problem of viewing output that does not fit on your screen. For example, range(100) will show the last 30ish lin

Answer 1

Say you're writing a program in Python and all it does is pretty print some stuff. The output is in prettiest_print_ever. You already do weird tricks importing fcntl, termios, struct and friends to get the terminal size so that you can use the full width of the terminal (if any); that also gives you the screen height, so it makes sense to use it. (That also means you've long given up any pretenses of cross-platform compatibility, too.)

Sure, you can reinvent the wheel, or you can rely on less like other programs do (e.g. git diff). This should be the outline of a solution:

def smart_print(prettiest_print_ever, terminal_height = 80):
  if len(prettiest_print_ever.splitlines()) <= terminal_height:
    #Python 3: make sure you write bytes!
    sys.stdout.buffer.write(prettiest_print_ever.encode("utf-8"))
  else
    less = subprocess.Popen("less", stdin=subprocess.PIPE)
    less.stdin.write(prettiest_print_ever.encode("utf-8"))
    less.stdin.close()
    less.wait()

Answer 2

just for fun :o)

Original version for Python2:

class Less(object):
    def __init__(self, num_lines):
        self.num_lines = num_lines
    def __ror__(self, other):
        s = str(other).split("\n")
        for i in range(0, len(s), self.num_lines):
            print "\n".join(s[i: i + self.num_lines])
            raw_input("Press <Enter> for more")

less = Less(num_lines=30)  
"\n".join(map(str, range(100))) | less

a Python3 version:

class Less(object):
    def __init__(self, num_lines):
        self.num_lines = num_lines
    def __ror__(self, other):
        s = str(other).split("\n")
        for i in range(0, len(s), self.num_lines):
            print(*s[i: i + self.num_lines], sep="\n")
            input("Press <Enter> for more")

less = Less(num_lines=30)  
"\n".join(map(str, range(100))) | less

Answer 3

if your data is json serilizable then you can try

import simplejson
print simplejson.dumps({'shipping-line': {'price': '0.00', 'code': 'Local Pickup (Portland, OR)', 'title': 'Local Pickup (Portland, OR)'}}, indent=4)

Output will be look something like

{
    "shipping-line": {
        "price": "0.00", 
        "code": "Local Pickup (Portland, OR)", 
        "title": "Local Pickup (Portland, OR)"
    }
}

this is specifically used to debug and to see the actual content......in well readble format..

EDIT:

if your screen is limited to 25 lines..........

import simplejson
data = simplejson.dumps({'shipping-line': {'price': '0.00', 'code': 'Local Pickup (Portland, OR)', 'title': 'Local Pickup (Portland, OR)'}}, indent=4)

cnt = 0

for line in data.split('\n'):
    cnt+=1
    print line
    raw_input() if cnt%25==0 else None