On Jul 16, 5:18 pm, Dan Bishop <[EMAIL PROTECTED]> wrote: > On Jul 16, 7:10 pm, Karthik Gurusamy <[EMAIL PROTECTED]> wrote:> Hi, > > > The string format operator, %, provides a functionality similar to the > > snprintf function in C. In C, the function does not know the type of > > each of the argument and hence relies on the embedded %<char> > > specifier to guide itself while retrieving args. > > > In python, the language already provides ways to know the type of an > > object. > > > So in > > > output = '%d foo %d bar" % (foo_count, bar_count), > > why we need to use %d? > > In order to distinguish between, for example: > > > > >>> '%c' % 42 > '*' > >>> '%d' % 42 > '42' > >>> '%e' % 42 > '4.200000e+01' > >>> '%f' % 42 > '42.000000' > >>> '%g' % 42 > '42' > >>> '%i' % 42 > '42' > >>> '%o' % 42 > '52' > >>> '%r' % 42 > '42' > >>> '%s' % 42 > '42'
Thanks. The above surprised me as I didn't expect that %s will accept 42. Looks like the implicit conversion doesn't work the other way. >>> '%s' % 42 '42' >>> '%d' % '42' Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: int argument required >>> Looks like %s can be used even when I'm sending non-strings. >>> '%s foo %s bar' % (25, 25.34) '25 foo 25.34 bar' >>> So %s seems to serve the multi-type placeholder. Karthik > >>> '%u' % 42 > '42' > >>> '%x' % 42 > > '2a' -- http://mail.python.org/mailman/listinfo/python-list
