Get the first element of each tuple in a list in Python [duplicate]

by

Use a list comprehension:

res_list = [x[0] for x in rows]

Below is a demonstration:

>>> rows = [(1, 2), (3, 4), (5, 6)]
>>> [x[0] for x in rows]
[1, 3, 5]
>>>

Alternately, you could use unpacking instead of x[0]:

res_list = [x for x,_ in rows]

Below is a demonstration:

>>> lst = [(1, 2), (3, 4), (5, 6)]
>>> [x for x,_ in lst]
[1, 3, 5]
>>>

Both methods practically do the same thing, so you can choose whichever you like.

More Related Contents:

  1. What is the result of % in Python?
  2. How do I get a decimal value when using the division operator in Python?
  3. What is the difference between ‘/’ and ‘//’ when used for division?
  4. How to sort a dataFrame in python pandas by two or more columns?
  5. Why isn’t my Pandas ‘apply’ function referencing multiple columns working? [closed]
  6. Why isn’t assigning to an empty list (e.g. [] = “”) an error?
  7. What is the right way to debug in iPython notebook?
  8. How to get current time in python and break up into year, month, day, hour, minute?
  9. Getting a default value on index out of range in Python [duplicate]
  10. Python 2.7: Print to File
  11. Why does updating one dictionary object affect other?
  12. What are the differences between bool() and operator.truth()?
  13. how to open chrome in incognito mode from Python
  14. Matplotlib just giving error messages
  15. TypeError: cannot perform reduce with flexible type
  16. Reading serial data in realtime in Python
  17. range(len(list)) or enumerate(list)? [duplicate]
  18. TypeError: unsupported operand type(s) for -: ‘list’ and ‘list’
  19. How to sort list of lists according to length of sublists [duplicate]
  20. python sys.exit not working in try [duplicate]
  21. Is there a reason Python 3 enumerates slower than Python 2?
  22. Have multiple commands when button is pressed
  23. downloading error using nltk.download()
  24. Auto-Loading a module on IPython startup
  25. Unknown error: Chrome failed to start: exited abnormally
  26. ImportError: DLL load failed: %1 is not a valid Win32 application for Python Matplotlib
  27. pprint dictionary on multiple lines
  28. Converting string to tuple without splitting characters
  29. How does all() in python work on empty lists
  30. Can Syntax Errors be handled?

Leave a Comment