# Regression Tests: Treebank Tokenizer

Some test strings.

```>>> s1 = "On a \$50,000 mortgage of 30 years at 8 percent, the monthly payment would be \$366.88."
>>> word_tokenize(s1)
['On', 'a', '\$', '50,000', 'mortgage', 'of', '30', 'years', 'at', '8', 'percent', ',', 'the', 'monthly', 'payment', 'would', 'be', '\$', '366.88', '.']
>>> s2 = "\"We beat some pretty good teams to get here,\" Slocum said."
>>> word_tokenize(s2)
['``', 'We', 'beat', 'some', 'pretty', 'good', 'teams', 'to', 'get', 'here', ',', "''", 'Slocum', 'said', '.']
>>> s3 = "Well, we couldn't have this predictable, cliche-ridden, \"Touched by an Angel\" (a show creator John Masius worked on) wanna-be if she didn't."
>>> word_tokenize(s3)
['Well', ',', 'we', 'could', "n't", 'have', 'this', 'predictable', ',', 'cliche-ridden', ',', '``', 'Touched', 'by', 'an', 'Angel', "''", '(', 'a', 'show', 'creator', 'John', 'Masius', 'worked', 'on', ')', 'wanna-be', 'if', 'she', 'did', "n't", '.']
>>> s4 = "I cannot cannot work under these conditions!"
>>> word_tokenize(s4)
['I', 'can', 'not', 'can', 'not', 'work', 'under', 'these', 'conditions', '!']
>>> s5 = "The company spent \$30,000,000 last year."
>>> word_tokenize(s5)
['The', 'company', 'spent', '\$', '30,000,000', 'last', 'year', '.']
>>> s6 = "The company spent 40.75% of its income last year."
>>> word_tokenize(s6)
['The', 'company', 'spent', '40.75', '%', 'of', 'its', 'income', 'last', 'year', '.']
>>> s7 = "He arrived at 3:00 pm."
>>> word_tokenize(s7)
['He', 'arrived', 'at', '3:00', 'pm', '.']
>>> s8 = "I bought these items: books, pencils, and pens."
>>> word_tokenize(s8)
['I', 'bought', 'these', 'items', ':', 'books', ',', 'pencils', ',', 'and', 'pens', '.']
>>> s9 = "Though there were 150, 100 of them were old."
>>> word_tokenize(s9)
['Though', 'there', 'were', '150', ',', '100', 'of', 'them', 'were', 'old', '.']
>>> s10 = "There were 300,000, but that wasn't enough."
>>> word_tokenize(s10)
['There', 'were', '300,000', ',', 'but', 'that', 'was', "n't", 'enough', '.']
```

Sentence tokenization in word_tokenize:

```>>> s11 = "I called Dr. Jones. I called Dr. Jones."
>>> word_tokenize(s11)
['I', 'called', 'Dr.', 'Jones', '.', 'I', 'called', 'Dr.', 'Jones', '.']
>>> s12 = ("Ich muss unbedingt daran denken, Mehl, usw. fur einen "
...        "Kuchen einzukaufen. Ich muss.")
>>> word_tokenize(s12)
['Ich', 'muss', 'unbedingt', 'daran', 'denken', ',', 'Mehl', ',', 'usw',
'.', 'fur', 'einen', 'Kuchen', 'einzukaufen', '.', 'Ich', 'muss', '.']
>>> word_tokenize(s12, 'german')
['Ich', 'muss', 'unbedingt', 'daran', 'denken', ',', 'Mehl', ',', 'usw.',
'fur', 'einen', 'Kuchen', 'einzukaufen', '.', 'Ich', 'muss', '.']
```

# Regression Tests: Regexp Tokenizer

```>>> s = ("Good muffins cost \$3.88\nin New York.  Please buy me\n"
...      "two of them.\n\nThanks.")
>>> s2 = ("Alas, it has not rained today. When, do you think, "
...       "will it rain again?")
>>> s3 = ("<p>Although this is <b>not</b> the case here, we must "
...       "not relax our vigilance!</p>")
```
```>>> regexp_tokenize(s2, r'[,\.\?!"]\s*', gaps=False)
[', ', '. ', ', ', ', ', '?']
>>> regexp_tokenize(s2, r'[,\.\?!"]\s*', gaps=True)
['Alas', 'it has not rained today', 'When', 'do you think',
'will it rain again']
```

Make sure that grouping parentheses don't confuse the tokenizer:

```>>> regexp_tokenize(s3, r'</?(b|p)>', gaps=False)
['<p>', '<b>', '</b>', '</p>']
>>> regexp_tokenize(s3, r'</?(b|p)>', gaps=True)
['Although this is ', 'not',
' the case here, we must not relax our vigilance!']
```

Make sure that named groups don't confuse the tokenizer:

```>>> regexp_tokenize(s3, r'</?(?P<named>b|p)>', gaps=False)
['<p>', '<b>', '</b>', '</p>']
>>> regexp_tokenize(s3, r'</?(?P<named>b|p)>', gaps=True)
['Although this is ', 'not',
' the case here, we must not relax our vigilance!']
```

Make sure that nested groups don't confuse the tokenizer:

```>>> regexp_tokenize(s2, r'(h|r|l)a(s|(i|n0))', gaps=False)
['las', 'has', 'rai', 'rai']
>>> regexp_tokenize(s2, r'(h|r|l)a(s|(i|n0))', gaps=True)
['A', ', it ', ' not ', 'ned today. When, do you think, will it ',
'n again?']
```

The tokenizer should reject any patterns with backreferences:

```>>> regexp_tokenize(s2, r'(.)\1')
Traceback (most recent call last):
...
ValueError: Regular expressions with back-references are
not supported: '(.)\\1'
>>> regexp_tokenize(s2, r'(?P<foo>)(?P=foo)')
Traceback (most recent call last):
...
ValueError: Regular expressions with back-references are
not supported: '(?P<foo>)(?P=foo)'
```

A simple sentence tokenizer '.(s+|\$)'

```>>> regexp_tokenize(s, pattern=r'\.(\s+|\$)', gaps=True)
['Good muffins cost \$3.88\nin New York',