Natural Language Processing · 免费预览
文本归一化与正则表达式
归一化流水线、正则表达式运算符、捕获组与替换，以及句子切分中的陷阱。
1. Text Normalization and Regular Expressions
Text Normalization and Regular Expressions
2. The regular expression operators
The regular expression operators
3. Tokenizing and rewriting with Python's re module
Tokenizing and rewriting with Python's re module
4. Reading a pattern
Which of these strings matches the regular expression D[a-z]{4}\d{2} (anchors omitted, so a match can occur anywhere)?
5. Counting matches
How many substrings of this log line match \d{3}-\d{4}?
"99-5981; 183-6326; 823-7318; 8789-6672; 256-9285."
6. Rewriting with capture groups
The substitution re.sub(r"(\w+) (\d+) (\w+)", r"\3-\1", s) is applied to s = "bay 09 south". What is the resulting string? (Type it exactly, lowercase.)
7. Word boundaries
Which of these strings contains a match for the pattern \bwake\b?
8. Counting the language of a pattern
How many strings of length 7 over the alphabet {0,1} end with 10? (That is, strings matching (0|1)*10 with total length exactly 7.)