Reference library

Lists & loops

Iterate, transform, and combine sequences with readable loop patterns.

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Lists & loops easy

Symmetric difference between two lists in Python

Find elements present in exactly one of two lists, preserving original order, with a simple Python function.

lists sets symmetric-difference
Python 
def symmetric_difference(list1, list2):
    """
    Return the symmetric difference of two lists.
    Elements present in exactly one of the lists, preserving order.
    """
    set1 = set(list1)
    set2 = set(list2)
    
    # Elements in list1 but not in list2
    diff1 = [x for x in list1 if x not in set2]
    # E…
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Lists & loops — Python code examples

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