Type Conversions

We can convert between various types of objects, often just by calling the type with the thing we want to convert:

>>> value = '32'
>>> value
'32'
>>> int(value)
32
>>> float(value)
32.0
>>> str( int( value )) # note `str` not `string`
'32'
>>> str( float( value ))
'32.0'
>>> value = '32.6'
>>> int(value)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '32.6'
>>> float( value )
32.6
>>> int( float (value ))
32
>>> int( round( float( value ), 0 ))
33
>>> round( 32.6, 0 )
33.0
>>> round( 32.6, 1 )
32.6
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '32.6'

Exercise

In the interpreter, multiply the strings ‘10’ and ‘20’ to get the integer result 200:

>>> first = '10'
>>> second = '20'
...
>>> print first * second # should print 200