Quick Reference
The Python set difference_update() method removes the items that exist in both sets.
Example 1:
x = {"Ferrari", "Maserati", "Alfa Romeo"}
y = {"Lamborghini", "Ferrari"}
x.difference_update(y)
print(x)Example 2:
x = {"Ferrari", "Maserati", "Alfa Romeo"}
y = {"Lamborghini", "Ferrari"}
x -= y
print(x)Note
In example 2, using the (-=) operator, sets can only be joined with other sets, NOT other iterables, as can be done in the first example. Using other iterables with the (-=) operator will raise an error.
Output
{'Alfa Romeo', 'Maserati'}Syntax
set.difference_update(set1, set2 ... etc.)
// or
set1 -= set2 | set3 ... etc.Parameters
Example 1:
| Parameter | Description |
|---|---|
| set1 | The set(s) to check for differences in (required) |
| set2 | The other set to search for equal items in |
| set3, set4, etc. | You can compare as many sets you like; separate the sets with a comma |
Example 2:
| Parameter | Description |
|---|---|
| set1 | The set(s) to check for differences in (required) |
| set2 | The other set to search for equal items in |
| set1 -= set2 | set3 ... etc. | The other set to search for equal items in; you can compare as many sets you like; separate the sets with | (a pipe operator) |
Python Notes:
- The most recent major version of Python is Python 3; however, Python 2 is still in use and quite popular, although not being updated with anything other than security updates
- Python uses new lines to complete a command, as opposed to other programming languages which often use semicolons or parentheses
- Python relies on indentation, using whitespace to define scope, such as the scope of loops, functions, and classes; other programming languages often use curly-brackets for this purpose
- Python string methods return new values, and DO NOT change the original string
- Python tuples are unchangeable after created (their items CANNOT be changed or re-ordered at a later point)
- Python sets are unordered (may appear in random orders when called), unchangeable (the value of individual items cannot be changed after creation), unindexed (items cannot be referred to by index or key), and duplicates are NOT ALLOWED
- As of v3.7, Python dictionaries are ordered and duplicates ARE ALLOWED; in v3.6 and earlier, dictionaries were unordered (did not have a defined order and could not be referred to using an index)
We’d like to acknowledge that we learned a great deal of our coding from W3Schools and TutorialsPoint, borrowing heavily from their teaching process and excellent code examples. We highly recommend both sites to deepen your experience, and further your coding journey. We’re just hitting the basics here at 1SMARTchicken.