python replace multiple characters in a string
<p>I want to encrypt a string in python. Every character in the char is mapped to some other character in the secret key. For example <code>'a'</code> is mapped to <code>'D'</code>, 'b' is mapped to <code>'d'</code>, <code>'c'</code> is mapped to <code>'1'</code> and so forth as shown below:</p>

<pre><code>char    = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
secretkey="Dd18Abz2EqNPWhYTOjBvtVlpXaH6msFUICg4o0KZwJeryQx3f9kSinRu5L7cGM"
</code></pre>

<p>If I choose the string <code>"Lets meet at the usual place at 9 am"</code> the output must be <code>"oABjMWAABMDBMB2AMvjvDPMYPD1AMDBMGMDW"</code></p>