[Tutor] really dumb questions
Sun, 10 Feb 2002 23:29:18 -0000
Just back from a week vacation so jumping in late...
> > I know that there is writelines, but as usual i can't
> figure out based on the Python documentation which hardly
> ever gives illustrative examples.
Thats why Beasleys book is good - it adds the examples ;-)
> >>> scooby_file=open("scooby.txt","w")
> >>> scooby_file.writelines(["Scooby","Dooby","Doo"])
> >>> scooby_file.close()
> Yields the file scooby.txt with the following data in it:
And if you want it on separate lines just add a '\n' to
f.writelines(map(lambda s: s+'\n', ["Scooby", "Dooby", "Doo"]))
Or do it more explicitly in a loop:
for line in ["Scooby", "Dooby", "Doo"]:
line = line + '\n'
That's all writelines() does internally, (without the \n malarky)
its nothing magic, just a handy shortcut to a common operation...
> > My other dumb question is this: how do i print a list
> without the leading and trailing brackets and commas?
> for item in [1,2,3]:
> print item, #don't miss that comma on the end,
But he asked for f.write not print so...
s = ''
for item in [1,2,3]:
s = s+str(item) # just convert to a string and concatenate
f.write(s) # then write the final string
> add the `x` thing it works but it adds single quotes to the
> output. How do you suppress those?
You don't need to. The interpreter adds those to show that
its a string. If you assign the result to a striong then
write the string it should work just fine:
> 'x' thing? You've lost me there.
Its the backtick technique for converting to a string.
Yep, just like that... Do you see a trend yet?
> ...the first element of sys.argv should give you
> what you want. ie.:
> import sys
And you could use the os.path functions to prepend
the current directory if desired.
prog_path = os.path.join(os.getcwd(),sys.argv)
Note: that's not tested but something very similar