ValueError: too many values to unpack

What you see

config = {"host": "localhost", "port": 8080}

for key, value in config:
    print(key, value)

Traceback (most recent call last):
  File "/home/me/project/main.py", line 3, in <module>
    for key, value in config:
        ^^^^^^^^^^
ValueError: too many values to unpack (expected 2)

What it means

key, value = something takes something apart into exactly two pieces. Here each something is one key of the dict, the string "host", which has four characters, so there are four pieces for two names.

Looping over a dict gives its keys, not its key and value pairs. That is the most common way to meet this error.

Why it happens

• Looping over a dict with two names, as in the example.
• A split() that found more parts than expected, as in name, email = "Ada, Lovelace, ada@example.com".split(",").
• A function that returns more values than the caller unpacks.
• Rows with more columns than names, from a CSV file or a database query.

How to fix it

For a dict, ask for the pairs with .items():

for key, value in config.items():
    print(key, value)

For text, cap the number of splits, or collect the rest with a starred name:

name, rest = line.split(",", 1)    # at most two parts
first, *others = line.split(",")   # first part, then a list of the rest

Example: a tuple with one item too many

point = (3, 4, 5)
x, y = point

Traceback (most recent call last):
  File "/home/me/project/main.py", line 2, in <module>
    x, y = point
    ^^^^
ValueError: too many values to unpack (expected 2, got 3)

Run on CPython 3.9.6, 3.10.22, 3.11.17, 3.12.15, 3.13.17, 3.14.9 and 3.15.1, on October 25, 2026.

How each Python version words it

Run on CPython 3.9.6, 3.10.22, 3.11.17, 3.12.15, 3.13.17, 3.14.9 and 3.15.1, on October 25, 2026.

Python 3.14 adds how many values it got, "expected 2, got 3", when the right side is a tuple, a list or a dict. For a string, a range or an iterator it still says only "expected 2", which is why the dict loop above prints no count: each item it unpacks is a key string.