Python ''.format(): "tuple index out of range"?
Consider the following snippet:
>>> def foo(port, out, udp=False, ipv6=False, data=''):
... if not data:
... data = 'foo {family} {:port} {direction}'.format(
... family=('ipv6' if ipv6 else 'ipv4'),
... port=port,
... directi开发者_运维百科on=('out' if out else 'in'))
... return data
...
>>> foo(12345, out=True)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 6, in foo
IndexError: tuple index out of range
As far as I know, the scoping of names look alright. What's with the cryptic error?
Watch the colon. Move it from the front of the port area:
Either
data = 'foo {family} {port:} {direction}'.format(
Or
data = 'foo {family} :{port} {direction}'.format(
The results of the two options are:
>>> foo(12345, out=True)
'foo ipv4 12345 out'
>>> foo(12345, out=True)
'foo ipv4 :12345 out'
{:port}
should be {port:}
.
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