Python Checking a string's first and last character

Question

can anyone please explain what is wrong with this code?

str1='"xxx"'
print str1
if str1[:1].startswith('"'):
    if str1[:-1].endswith('"'):
        print "hi"
    else:
        print "condition fails"
else:
    print "bye"

The output I got is:

Condition fails

but I expected it to print hi instead.

Asked By: Chuvi

||

Source

Answer 1

You are testing against the string minus the last character:

>>> '"xxx"'[:-1]
'"xxx'

Note how the last character, the ", is not part of the output of the slice.

I think you wanted just to test against the last character; use [-1:] to slice for just the last element.

However, there is no need to slice here; just use str.startswith() and str.endswith() directly.

Answered By: Martijn Pieters

Answer 2

When you say [:-1] you are stripping the last element. Instead of slicing the string, you can apply startswith and endswith on the string object itself like this

if str1.startswith('"') and str1.endswith('"'):

So the whole program becomes like this

>>> str1 = '"xxx"'
>>> if str1.startswith('"') and str1.endswith('"'):
...     print "hi"
>>> else:
...     print "condition fails"
...
hi

Even simpler, with a conditional expression, like this

>>> print("hi" if str1.startswith('"') and str1.endswith('"') else "fails")
hi

Answered By: thefourtheye

Answer 3

When you set a string variable, it doesn’t save quotes of it, they are a part of its definition.
so you don’t need to use :1

Answered By: Farhadix

Answer 4

You should either use

if str1[0] == '"' and str1[-1] == '"'

or

if str1.startswith('"') and str1.endswith('"')

but not slice and check startswith/endswith together, otherwise you’ll slice off what you’re looking for…

Answered By: Roberto

Python Checking a string's first and last character

Question:

Answers: