Compute the insertion point for x in a sorted sequence using binary search.

Signal the intent to locate the proper insertion index for maintaining sorted order without modifying the sequence.

When you need to find where to insert a new element into a sorted list, e.g., before inserting to avoid duplicates or to implement binary search‑based algorithms.

Used in algorithms that require maintaining sorted collections, such as inserting into a sorted list, implementing bisect‑based search, or building custom sorted containers.

bisect.bisect_left(seq, x)

bisect.bisect_left(sequence, item)

seq: a sorted sequence (e.g., list of numbers); x: the item to insert.

• list
• sorted list
• bisect_right
• insort_left
• insort_right
• binary search

• bisect.bisect_right(seq
• x) (returns insertion point after existing entries)
• bisect.insort_left(seq
• x) (inserts x before any existing entries).

Using an unsorted sequence leads to incorrect insertion point; confusing bisect_left with bisect_right causes off‑by‑one errors; forgetting that the input must be sorted beforehand.

bisect.bisect_right (returns insertion point after any existing entries of x); bisect.insort_left (inserts x while keeping list sorted).

Confusing bisect_left with bisect_right can cause off‑by‑one errors; assuming the input is sorted when it is not yields undefined behavior.

• bisect.bisect_right
• bisect.insort_left
• bisect.insort_right

Returns the leftmost index where x can be inserted without violating order; equal elements are placed after the returned index.

Indicates the programmer’s intent to maintain sorted order and to query the insertion point without altering the original sequence.

bisect left: where to insert to keep sorted

Runs in O(log n) time due to binary search.

bisect.insort_left (insert while keeping sorted)