Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

Python: iter() function

iter() function

The iter() function returns an iterator object.

Version:

(Python 3.2.5)

Syntax:

iter(object[, sentinel])

Parameter:

Name Description Required /
Optional
object An object whose iterator has to be created (can be sets, tuples, etc.) Required
sentinel special value that is used to represent the end of a sequence Optional

The following example reads a file until the readline() method returns an empty string:

with open('mydata.txt') as fp:
    for line in iter(fp.readline, ''):
        process_line(line)

Example: Python: iter() function

# list of letters
letters = ['P', 'y', 't', 'h', 'o', 'n']

lettersIter = iter(letters)

# prints 'P'
print(next(lettersIter))

# prints 'y'
print(next(lettersIter))

# prints 't'
print(next(lettersIter))

# prints 'h'
print(next(lettersIter))

# prints 'o'
print(next(lettersIter))

# prints 'n'
print(next(lettersIter))

Output:

P
y
t
h
o
n

Pictorial Presentation:

Python: Built-in-function - iter() function

Pictorial Presentation:

Python: Built-in-function - iter() function

Python Code Editor:

Previous: issubclass()
Next: len()

Test your Python skills with w3resource's quiz



Python: Tips of the Day

Find current directory and file's directory:

To get the full path to the directory a Python file is contained in, write this in that file:

import os 
dir_path = os.path.dirname(os.path.realpath(__file__))

(Note that the incantation above won't work if you've already used os.chdir() to change your current working directory, since the value of the __file__ constant is relative to the current working directory and is not changed by an os.chdir() call.)

To get the current working directory use

import os
cwd = os.getcwd()

Documentation references for the modules, constants and functions used above:

  • The os and os.path modules.
  • The __file__ constant
  • os.path.realpath(path) (returns "the canonical path of the specified filename, eliminating any symbolic links encountered in the path")
  • os.path.dirname(path) (returns "the directory name of pathname path")
  • os.getcwd() (returns "a string representing the current working directory")
  • os.chdir(path) ("change the current working directory to path")

Ref: https://bit.ly/3fy0R6m