Python float numbers lose accuracy out of a tuple?

Question

This next behaviour befuddles me, any explanation would be appreciated.

>>> a = (0.1457164443693023, False)
>>> print a
(0.1457164443693023, False)
>>> print a[0]
0.145716444369

Using python 2.7

Answer 1

The only difference is the print. The number doesn't change, just its representation. You can reduce your problem to:

>>> 0.1457164443693023
0.1457164443693023
>>> print 0.1457164443693023
0.145716444369

(I guess (and this is only and merely a guess) this boils down to __repr__ vs __str__ or something along this line)

Answer 2

The first calls __ repr __ , the second __ str __

a = (0.1457164443693023, False)
print a
>>> (0.1457164443693023, False)
print a[0]
>>> 0.145716444369

print repr(a[0])
>>> 0.1457164443693023
print str(a[0])
>>> 0.145716444369

For some design reason Double.__ str __() returns fewer decimals.

Answer 3

Looks like python does not print the full accuracy of a float, but it is still there.

>>> a = (0.1457164443693023, False)

>>> print a
(0.1457164443693023, False)

>>> print repr(a[0])
0.1457164443693023