CODEWITHSUNDEEP
pythonpython-3.x
ymc
ymc

Reputation: 77

Translating python2 itertools.izip to python3 zip

I am in the process of translating my python2 code to python3

One error I am getting is that I need to replace itertools.izip with zip

I did that but I am still getting errors.

I found that these two functions are not really equivalent. Here is an example:

from itertools import izip
for a,b in izip(range(3), "ABC"):
  print(a,b)

The above script gave me the following outputounder python2:

(0, 'A')
(1, 'B')
(2, 'C')

If I simply replace izip with zip and run under python3:

for a,b in zip(range(3),"ABC"):
  print(a,b)

The output I got is different:

0 A
1 B
2 C

How do I fix my python2 code such that it will generate the same output as before? Thanks a lot in advance.

Upvotes: 1

Views: 478

Answers (2)

frost-nzcr4
frost-nzcr4

Reputation: 1620

Upgrading your code with 2to3 and modernize tools could be faster and less error-prone. And now is the right time to start writing tests because print is not a best tool to assert the values.

Upvotes: 0

Jan Pokorný
Jan Pokorný

Reputation: 1868

The behavior you observe isn't caused by the zipping, but by the print function/statement.

In Python 2, it has this syntax:

print x, ...

In Python 3, it has this syntax:

print(x, ...)

Thus in Python 2, print(a,b) prints the one argument, tuple (a,b). In Python 3, print(a,b) prints the two arguments a and b separately, separated by the default separator (space).

Upvotes: 2

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