## genetics.complementary_dna()


Create the complementary DNA sequence.


Usage

``` python
genetics.complementary_dna(dna_sequence)
```


Generates the complementary strand by replacing each nucleotide with its complement: A↔︎T and G↔︎C. Non-standard nucleotides are replaced with 'X'.


## Parameters


`dna_sequence: str`  
The DNA sequence to complement. Case-insensitive.


## Returns


`str: str`  
The complementary DNA sequence as a string.


## Examples

``` python
    >>> complementary_dna("ATGC")
```

    'TACG'

``` python
    >>> complementary_dna("ATGN")
```

    'TACGX'