Creating a float in a list of objects

Question

I have a list of objects,

l = (('a1', 1.96256684), ('b3', 1.36), ('e2', 0.5715))

I want to be able to format the numbers to a certain number of decimal places (4) in order to get an output like

a1 1.9626 b3 1.3600 e3 0.5715

I tried the method described here (using isalpha) but get the error

AttributeError: 'tuple' object has no attribute 'isalpha'

I'm wondering if it's because the alphabetic letters have numbers attached to them? But then I would think it would just return False instead of giving me an error.

Thank you for any help or adivce

Can you upload your code? You could be using isalpha on the tuple instead of the string — lordingtar, Apr 11 '17 at 18:32

score 2 · Accepted Answer · answered Apr 11 '17 at 18:33

2

You probably want to format the strings using .format.

>>> '{:0.4f}'.format(1.36)
'1.3600'
>>> '{:0.4f}'.format(1.96256684)
'1.9626'

The full code could look something like:

' '.join('{} {:0.4f}'.format(*t) for t in l)

answered Apr 11 '17 at 18:33

mgilson

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`' '.join('{0[0]} {0[1]:0.4f}'.format(t) for t in l)` also works and avoids the tuple unpacking, but I don't like it as much :-) – mgilson Apr 11 '17 at 18:35

wim · Answer 2 · 2017-04-11T18:42:26.560

2

Print statement will join with spaces anyway, so you can unpack the args with a splat:

>>> print(*(f'{s} {f:.4f}' for s,f in l))
a1 1.9626 b3 1.3600 e2 0.5715

This uses the literal string interpolation feature, new in Python 3.6.

edited Apr 11 '17 at 18:42

answered Apr 11 '17 at 18:38

wim

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You might want to point out t hat this is python3.6+ only -- And you might want to mention that you are using f-strings. I appreciate their use, but it's probably good to give people something to google to find out more :-). – mgilson Apr 11 '17 at 18:41
@mgilson Added. Feel free to edit my post directly next time. – wim Apr 11 '17 at 18:42

Creating a float in a list of objects

2 Answers2