Difference between dict.clear() and assigning {} in Python

by

If you have another variable also referring to the same dictionary, there is a big difference:

>>> d = {"stuff": "things"}
>>> d2 = d
>>> d = {}
>>> d2
{'stuff': 'things'}
>>> d = {"stuff": "things"}
>>> d2 = d
>>> d.clear()
>>> d2
{}

This is because assigning d = {} creates a new, empty dictionary and assigns it to the d variable. This leaves d2 pointing at the old dictionary with items still in it. However, d.clear() clears the same dictionary that d and d2 both point at.

More Related Contents:

  1. Remove string in python dictionary value
  2. python building coder for ceasar cipher
  3. I don’t know how to display step 3 for this assignment
  4. Python 2.7.10: Using LAMBDA and LOGICAL operators in DICT to choose a case
  5. How to make a dict from n’th indices of tuples in list
  6. Create a dictionary with comprehension
  7. Loop through all nested dictionary values?
  8. How to use a dot “.” to access members of dictionary?
  9. Alternative to dict comprehension prior to Python 2.7
  10. How do I convert this list of dictionaries to a csv file?
  11. How to index into a dictionary?
  12. Sorting a dictionary by value then key
  13. How can I initialize a dictionary of distinct empty lists in Python?
  14. How to add multiple values to a dictionary key?
  15. How do I sort a dictionary by key?
  16. Appending a dictionary to a list in a loop
  17. Calculate difference in keys contained in two Python dictionaries
  18. How to search if dictionary value contains certain string with Python
  19. Is it possible to assign the same value to multiple keys in a dict object at once?
  20. Creating an Ordered Counter
  21. How do I sort this list in Python, if my date is in a String?
  22. How can I extract all values from a dictionary in Python?
  23. Will OrderedDict become redundant in Python 3.7?
  24. Mapping over values in a python dictionary
  25. Search a list of dictionaries in Python
  26. Nested Dictionary to MultiIndex pandas DataFrame (3 level)
  27. Accessing values nested within dictionaries
  28. How do I send list of dictionary as Body parameter in FastAPI?
  29. How do I re-map python dict keys
  30. How do I merge dictionaries together in Python?

Leave a Comment