How to check whether a str(variable) is empty or not?

Question

How do I make a:

if str(variable) == [contains text]:

condition?

(or something, because I am pretty sure that what I just wrote is

Answer 1

For python 3, you can use bool()

>>> bool(None)
False
>>> bool("")
False
>>> bool("a")
True
>>> bool("ab")
True
>>> bool("9")
True

Answer 2

Some time we have more spaces in between quotes, then use this approach

a = "   "
>>> bool(a)
True
>>> bool(a.strip())
False

if not a.strip():
    print("String is empty")
else:
    print("String is not empty")

Answer 3

use "not" in if-else

x = input()

if not x:
   print("Value is not entered")
else:
   print("Value is entered")

Answer 4

How do i make an: if str(variable) == [contains text]: condition?

Perhaps the most direct way is:

if str(variable) != '':
  # ...

Note that the if not ... solutions test the opposite condition.

Answer 5

Just say if s or if not s. As in

s = ''
if not s:
    print 'not', s

So in your specific example, if I understand it correctly...

>>> import random
>>> l = ['', 'foo', '', 'bar']
>>> def default_str(l):
...     s = random.choice(l)
...     if not s:
...         print 'default'
...     else:
...         print s
... 
>>> default_str(l)
default
>>> default_str(l)
default
>>> default_str(l)
bar
>>> default_str(l)
default

Answer 6

Empty strings are False by default:

>>> if not "":
...     print("empty")
...
empty