Question: I'm trying to do a small decoder.  

I want to assign the value `'a'` to the special letter `"("`  

example: `( = "a"`  

and if I input `"("` it prints it to `"a"` like: 

If I enter `"(%!)("`:

It prints the equivalent for each character like: 

```
LadyBa

```

Hope you understand what I mean!  

I know it need unicode or something like that but I'm not very good at python  

I'm trying to learn.  

Working on windows python 3.3

Answer: 
you can use `str.translate`:

```
In [7]: trans = str.maketrans("(","a")

In [8]: "(bcd(".translate(trans)
Out[8]: 'abcda'

```

> 
> S.translate(table [,deletechars]) -> string
> 
> 
> Return a copy of the string S, where all characters occurring in the
>  optional argument deletechars are removed, and the remaining
>  characters have been mapped through the given translation table, which
>  must be a string of length 256 or None. If the table argument is None,
>  no translation is applied and the operation simply removes the
>  characters in deletechars.
> 
> 
>
EDIT: this is good, thanks to Ashwini Chaudhary

```
>>> d = {'(': 'a'}
>>> "".join(d.get(x,x) for x in 'text with m(ny letters')
'text with many letters'

```

This is a longer solution but does the equivalent:

So you want to translate letters and keep thoos untouched that you do not know?

```
>>> d = {'(': 'a'}
>>> ''.join(map(lambda letter: d.get(letter, letter), 'text with m(ny letters'))
'text with many letters'

```

**Explanation**

---

This

```
d.get(letter, letter)

```

tries to find the letter in d and if not present returns letter (the second letter)

---

```
lambda letter: lalala

```

is the same as 

```
def f(letter):
    return lalala
f # return f

```

---

```
map(function, list) 

```

does this:

```
[function(element) for element in list]

```

which is a short form of

```
l = []
for element in list:
    l.append(function(element))
l # returns that list

```

---

```
''.join(list)

```

is the same as

```
string = ''
for element in list:
    string += element
string # return string as result

```