Module loda.oeis.sequence
Integer sequence model.
Classes
class Sequence (id: int, name='', terms=[])-
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@functools.total_ordering class Sequence: def __init__(self, id: int, name="", terms=[]): self.id = id self.name = name self.terms = terms def __str__(self) -> str: return "{}: {}".format(self.id_str(), self.name) def __eq__(self, other) -> bool: return self.id == other.id and self.terms == other.terms def __lt__(self, other) -> bool: if self.terms < other.terms: return True if self.terms == other.terms: return self.id < other.id return False def id_str(self) -> str: return "A{:06}".format(self.id) @classmethod def load_oeis(cls, oeis_path: str) -> list: """ Load sequences from `stripped` from `names` files. """ seqs = [] # load sequence terms stripped = os.path.join(oeis_path, "stripped") with open(stripped) as file: pattern = re.compile("^A([0-9]+) ,([\\-0-9,]+),$") for line in file: match = cls.__parse_line(line, pattern) if not match: continue id = int(match.group(1)) cls.__fill_seqs(seqs, id) seqs[id].id = id terms_str = match.group(2).split(",") seqs[id].terms = [int(t) for t in terms_str] # load sequence names names = os.path.join(oeis_path, "names") with open(names) as file: pattern = re.compile("^A([0-9]+) (.+)$") for line in file: match = cls.__parse_line(line, pattern) if not match: continue id = int(match.group(1)) cls.__fill_seqs(seqs, id) name = match.group(2) seqs[id].name = name return seqs @classmethod def __parse_line(cls, line: str, pattern): line = line.strip() if len(line) == 0 or line.startswith("#"): return None match = pattern.match(line) if not match: raise ValueError("parse error: {}".format(line)) return match @classmethod def __fill_seqs(cls, seqs: list, id: int): current_size = len(seqs) for i in range(current_size, id+2): seqs.append(Sequence(i, "", [])) def load_b_file(self, path: str) -> list: """ Load additional terms from a b-file. Args: path: Either path to a b-file (uncompressed `b*.txt` file) or a folder that contains the b-files in sub-directories, e.g. `b/123/b123456.txt`. """ terms = [] txt = "b{:06}.txt".format(self.id) if len(path) == 0 or os.path.isdir(path): dir = "{:03}".format(self.id//1000) path = os.path.join(path, "b", dir, txt) if not os.path.isfile(path): b_url = "http://api.loda-lang.org/miner/v1/oeis/{}.gz".format(txt) print("Fetching {}".format(b_url)) req = requests.get(b_url) gz_path = path + ".gz" with open(gz_path, 'wb') as gz: gz.write(req.content) subprocess.run(["gunzip", gz_path]) with open(path) as b_file: expected_index = -1 for line in b_file: line = line.strip() if len(line) == 0 or line[0] == "#": continue fields = line.split() if len(fields) < 2: raise ValueError("unexpected line: {}".format(line)) index = int(fields[0]) value = int(fields[1]) if expected_index == -1: expected_index = index if index != expected_index: raise ValueError("unexpected index: {}".format(index)) terms.append(value) expected_index += 1 terms = self.__align(terms) if terms is None: raise ValueError("unexpected terms in b-file") if len(terms) < len(self.terms): terms = self.terms elif terms[0:len(self.terms)] != self.terms: raise ValueError("unexpected terms in b-file") return terms def __align(self, terms: list, max_offset: int = 10) -> list: """Align terms from a b-file possible by shifting by an offset""" # check if they agree on prefix already min_length = min(len(self.terms), len(terms)) if self.terms[0:min_length] == terms[0:min_length]: return terms # try to align them for offset in range(1, max_offset+1): if offset >= min_length: break agree_pos = True agree_neg = True for i in range(min_length): if i+offset < len(terms) and terms[i + offset] != self.terms[i]: agree_pos = False if i+offset < len(self.terms) and terms[i] != self.terms[i+offset]: agree_neg = False if agree_pos: return terms[offset:] if agree_neg: result = self.terms[0:offset] result.extend(terms) return result return None @classmethod def load_id_list(cls, path: str) -> list: """Load sequence IDs from a text file""" ids = [] with open(path) as list_file: pattern = re.compile("^A([0-9]+)(:?.*)$") for line in list_file: match = cls.__parse_line(line, pattern) if not match: continue ids.append(int(match.group(1))) return idsStatic methods
def load_id_list(path: str) ‑> list-
Load sequence IDs from a text file
def load_oeis(oeis_path: str) ‑> list-
Load sequences from
strippedfromnamesfiles.
Methods
def id_str(self) ‑> str-
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def id_str(self) -> str: return "A{:06}".format(self.id) def load_b_file(self, path: str) ‑> list-
Expand source code
def load_b_file(self, path: str) -> list: """ Load additional terms from a b-file. Args: path: Either path to a b-file (uncompressed `b*.txt` file) or a folder that contains the b-files in sub-directories, e.g. `b/123/b123456.txt`. """ terms = [] txt = "b{:06}.txt".format(self.id) if len(path) == 0 or os.path.isdir(path): dir = "{:03}".format(self.id//1000) path = os.path.join(path, "b", dir, txt) if not os.path.isfile(path): b_url = "http://api.loda-lang.org/miner/v1/oeis/{}.gz".format(txt) print("Fetching {}".format(b_url)) req = requests.get(b_url) gz_path = path + ".gz" with open(gz_path, 'wb') as gz: gz.write(req.content) subprocess.run(["gunzip", gz_path]) with open(path) as b_file: expected_index = -1 for line in b_file: line = line.strip() if len(line) == 0 or line[0] == "#": continue fields = line.split() if len(fields) < 2: raise ValueError("unexpected line: {}".format(line)) index = int(fields[0]) value = int(fields[1]) if expected_index == -1: expected_index = index if index != expected_index: raise ValueError("unexpected index: {}".format(index)) terms.append(value) expected_index += 1 terms = self.__align(terms) if terms is None: raise ValueError("unexpected terms in b-file") if len(terms) < len(self.terms): terms = self.terms elif terms[0:len(self.terms)] != self.terms: raise ValueError("unexpected terms in b-file") return termsLoad additional terms from a b-file.
Args
path- Either path to a b-file (uncompressed
b*.txtfile) or a folder that contains the b-files in sub-directories, e.g.b/123/b123456.txt.