DevEquiv

    PHP implode() Equivalent in Python

    Python's str.join() does the same job as PHP's implode(), but the separator and the list swap positions, and Python requires every element to already be a string.

    Close equivalent

    PHP source
    implode()
    Closest Python API
    str.join()

    Main limitation: PHP `implode($glue, $array)` takes the separator first, then the array; Python `sep.join(iterable)` is called *on* the separator string, with the iterable as the argument — the calling convention is inverted, not just the argument order.

    How to use each function

    Before comparing the two, here's how implode() and str.join() work on their own.

    PHP: implode()

    implode(string $separator, array $array): string

    Joins the elements of an array into a single string, placing $separator between each element. Non-string elements (integers, floats, booleans) are automatically converted to strings. The $separator may be omitted, defaulting to an empty string.

    Returns: The concatenated string.

    PHP 
    implode(", ", ["red", "green", "blue"]);
// "red, green, blue"

    Python: str.join()

    separator.join(iterable)

    Joins the strings in iterable using separator, called as a method on the separator itself rather than passed as an argument to a free function. Every element must already be a str — non-string items raise a TypeError and must be converted first, e.g. with str() inside a generator expression.

    Returns: The concatenated string.

    Python 
    ", ".join(["red", "green", "blue"])
# 'red, green, blue'

    Quick mapping

    PHP implode()
    Closest Python API str.join()

    How it differs

    • PHP implode($glue, $array) takes the separator first, then the array; Python sep.join(iterable) is called *on* the separator string, with the iterable as the argument — the calling convention is inverted, not just the argument order.
    • PHP automatically converts non-string elements (integers, floats, booleans) to strings when joining; Python's str.join() raises a TypeError if any element isn't already a str — you must map elements through str() first, e.g. ",".join(str(x) for x in items).
    • PHP's implode($array) allows omitting the glue entirely, defaulting to an empty string separator; Python has no such shorthand — you must always pass an explicit separator, even if it's "".

    Examples

    Basic join

    PHP 
    implode(", ", ["a", "b", "c"]);
// "a, b, c"
    Python 
    ", ".join(["a", "b", "c"])
# "a, b, c"
    Same result, but note the separator is the receiver of the method call in Python, not an argument.

    Joining numbers (requires explicit conversion in Python)

    PHP 
    implode(",", [1, 2, 3]);
// "1,2,3"
    Python 
    ",".join(str(n) for n in [1, 2, 3])
# "1,2,3"
    PHP silently stringifies the integers; Python's join() would raise a TypeError without the explicit str() conversion inside the generator expression.

    Edge cases

    Edge case

    Joining an empty array/list produces an empty string in both languages — this edge case matches exactly.

    Edge case

    A common Python mistake when porting: forgetting to convert numbers to strings before joining raises TypeError: sequence item 0: expected str instance, int found — always wrap with map(str, ...) or a generator expression when the source list might contain non-strings.

    References

    • PHP Manual — implode — checked 2026-07-29
    • Python docs — str.join() (v3.x) — checked 2026-07-29

    Last verified 2026-07-29.