CODEWITHSUNDEEP
python-3.x
user2755407
user2755407

Reputation: 348

Python3.5.2 Reversed method string

>>> x = "hello world"
>>> y = reversed(x)
>>> z = ''.join(y)
>>> z
'dlrow olleh'
>>> y
<reversed object at 0x7f2871248b38>
>>> ''.join(y)
''
>>> x
'hello world'
>>> ''.join(y)
''
>>> z = ''.join(y)
>>> z
''

Why I am getting the value of z next time as blank string after doing join operation in reversed function

Upvotes: 0

Views: 36

Answers (1)

BlueSheepToken
BlueSheepToken

Reputation: 6149

This is because reversed returns an iterator, when you apply an operation on it, it "consumes" the element. If you want to store the result of reversed in a variable, join is a good way to do it.

from collections.abc import Iterator

print(isinstance(reversed("hello world"), Iterator)) # True

it = reversed("hello world")
for x in it:
    print(x) # Prints the letters

for x in it:
    print(x) # Do not print them, there are already "consumed"

Upvotes: 2

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