Set & Frozenset functions in Python (4)

Buy Me a Coffee☕

*Memo:

• My post explains set and frozenset functions (1).
• My post explains set and frozenset functions (2).
• My post explains set and frozenset functions (3).
• My post explains set and frozenset functions (5).
• My post explains set and frozenset functions (6).
• My post explains set and frozenset functions (7).
• My post explains a set (1).
• My post explains a frozenset (1).

difference() can return the elements in the set or frozenset which aren't in *others (Difference: A - B) as shown below:

*Memo:

• The 1st arguments are *others(Optional-Default:()-Type:Iterable):
  • Don't use any keywords like *others=, others=, etc.
• difference() creates a copy.
• - can do difference(), creating a copy and supporting set and frozenset.

<Set>:

A = {10, 20, 30, 40}
B = {10, 30, 50}
C = {30, 40}

print(A.difference(B))
print(A - B)
# {40, 20}

print(A.difference(C))
print(A - C)
# {10, 20}

print(B.difference(C))
print(B - C)
# {10, 50}

print(A.difference(B, C))
print(A - B - C)
# {20}

print(A.difference())
# {40, 10, 20, 30}

<Frozenset>:

A = frozenset([10, 20, 30, 40])
B = frozenset([10, 30, 50])
C = frozenset([30, 40])

print(A.difference(B))
print(A - B)
# frozenset({40, 20})

print(A.difference(C))
print(A - C)
# frozenset({10, 20})

print(B.difference(C))
print(B - C)
# frozenset({10, 50})

print(A.difference(B, C))
print(A - B - C)
# frozenset({20})

print(A.difference())
# frozenset({40, 10, 20, 30})

difference_update() can return the elements in the set which aren't in *others (Difference: A - B) as shown below:

*Memo:

• The 1st arguments are *others(Optional-Default:()-Type:Iterable):
  • Don't use any keywords like *others=, others=, etc.
• difference_update() doesn't create a copy.
• difference_update() doesn't exist for a frozenset.
• -= with or without | can do difference_update(), creating a copy and supporting set and frozenset.

<Set>:

A = {10, 20, 30, 40}
B = {10, 30, 50}
C = {30, 40}

A_ = A.copy()
A_.difference_update(B)
A_ -= B

print(A_)
# {20, 40}

A_ = A.copy()
A_.difference_update(C)
A_ -= C

print(A_)
# {20, 10}

B_ = B.copy()
B_.difference_update(C)
B_ -= C

print(B_)
# {10, 50}

A_ = A.copy()
A_.difference_update(B, C)
A_ -= B | C

print(A_)
# {20}

A_ = A.copy()
A_.difference_update()

print(A_)
# {40, 10, 20, 30}

<Frozenset>:

A = frozenset([10, 20, 30, 40])
B = frozenset([10, 30, 50])
C = frozenset([30, 40])

A_ = A.copy()
A_ -= B

print(A_)
# frozenset({40, 20})

A_ = A.copy()
A_ -= C

print(A_)
# frozenset({10, 20})

B_ = B.copy()
B_ -= C

print(B_)
# frozenset({10, 50})

A_ = A.copy()
A_ -= B | C

print(A_)
# frozenset({20})