pycangjie documentation - The Cangjie class

The Cangjie class

Now this is really the interesting part: it is the actual entry point to the library. For everything worth doing with pycangjie, you will want to get a hold on a Cangjie object.

It has 2 attributes:

• version is an int representing the version of the Cangjie input method you are interested in.

• filter_flags is an int corresponding to how you want to filter the output of the get_characters() query method.

First step: get a Cangjie object

Given that everything comes out of it, you must create a Cangjie object before you do anything else, for example:

import cangjie

cj = cangjie.Cangjie(cangjie.versions.CANGJIE3,
                     cangjie.filters.BIG5 | cangjie.filters.HKSCS)

The first parameter is one of the supported versions, and the third is a bitwise OR of the available output filters.

These will have an impact on the get_characters() query method.

Note that in the example above, given the output filters that have been used, the only characters which would be returned are the ones which are part of the Big 5 encoding and the Hong Kong Supplemental Character Set.

Output filters thus control the set of characters which will be returned, not the ones which are filtered out.

Querying for characters

There are three query methods.

First, and most importantly, get_characters() returns a list of characters corresponding to a given Cangjie code.

This is really what is intended by a Cangjie input method: the user types an input code, and expects one or more characters in return.

Here is an example of usage:

# cj is a Cangjie object
chars = cj.get_characters("abcd")

After execution of the above, chars will be a list of one or more CangjieChar instances corresponding to the “abcd” code in the Cangjie version passed to the constructor of the Cangjie class.

Wildcards (“”) are supported inside a code. For example, the “dd” code could be used.

It is often desired to show the user the radical corresponding to the characters they input, rather than (or along with) the latin letters they actually type.

You can do that with the get_radical() method, used as follows:

# cj is a Cangjie object
radical = cj.get_radical("d");

After execution, radical contains the radical corresponding to the “d” code.

Finally, users (especially Quick users) often want a convenient way to input punctuation and symbols without knowing their Cangjie code.

As such, we provide the get_characters_by_shortcode() method, which is used in exactly the same way as the get_characters() one:

# cj is a Cangjie object
chars = cj.get_characters_by_shortcode(",");

After execution, chars would contain a CangjieChar instance for each fullwidth / Chinese comma.

Validating user input

In your application, you might want to check whether the user input are valid keys of Cangjie codes (to pass them to the get_characters() method), or not (for example, to pass other characters to the get_characters_by_shortcode() method).

You can do that with the is_input_key() method:

# cj is a Cangjie object
cj.is_input_key("a"); # This is True
cj.is_input_key("@"); # This is False