nltk.induce_pcfg()¶

nltk.induce_pcfg(start, productions)[source]¶

Induce a PCFG grammar from a list of productions.

The probability of a production A -> B C in a PCFG is:

count(A -> B C)

P(B, C | A) = ————— where * is any right hand side

count(A -> *)

Parameters:	start (Nonterminal) – The start symbol productions (list(Production)) – The list of productions that defines the grammar