`ratio`

()

`ratio`

()Return a measure of the sequences’ similarity as a float in the range [0, 1].

Where T is the total number of elements in both sequences, and M is the number of matches, this is 2.0*M / T. Note that this is `1.0`

if the sequences are identical, and `0.0`

if they have nothing in common.

This is expensive to compute if `get_matching_blocks()`

or `get_opcodes()`

hasn’t already been called, in which case you may want to try `quick_ratio()`

or `real_quick_ratio()`

first to get an upper bound.

{note}Caution: The result of a

`ratio()`

call may depend on the order of the arguments. For instance:`>>> SequenceMatcher(None, 'tide', 'diet').ratio() 0.25 >>> SequenceMatcher(None, 'diet', 'tide').ratio() 0.5`

**Related Reading**