# encoding: utf-8 """ Utilities for working with strings and text. Inheritance diagram: .. inheritance-diagram:: IPython.utils.text :parts: 3 """ from __future__ import absolute_import import os import re import sys import textwrap from string import Formatter from IPython.testing.skipdoctest import skip_doctest_py3, skip_doctest from IPython.utils import py3compat # datetime.strftime date format for ipython if sys.platform == 'win32': date_format = "%B %d, %Y" else: date_format = "%B %-d, %Y" class LSString(str): """String derivative with a special access attributes. These are normal strings, but with the special attributes: .l (or .list) : value as list (split on newlines). .n (or .nlstr): original value (the string itself). .s (or .spstr): value as whitespace-separated string. .p (or .paths): list of path objects (requires path.py package) Any values which require transformations are computed only once and cached. Such strings are very useful to efficiently interact with the shell, which typically only understands whitespace-separated options for commands.""" def get_list(self): try: return self.__list except AttributeError: self.__list = self.split('\n') return self.__list l = list = property(get_list) def get_spstr(self): try: return self.__spstr except AttributeError: self.__spstr = self.replace('\n',' ') return self.__spstr s = spstr = property(get_spstr) def get_nlstr(self): return self n = nlstr = property(get_nlstr) def get_paths(self): from path import path try: return self.__paths except AttributeError: self.__paths = [path(p) for p in self.split('\n') if os.path.exists(p)] return self.__paths p = paths = property(get_paths) # FIXME: We need to reimplement type specific displayhook and then add this # back as a custom printer. This should also be moved outside utils into the # core. # def print_lsstring(arg): # """ Prettier (non-repr-like) and more informative printer for LSString """ # print "LSString (.p, .n, .l, .s available). Value:" # print arg # # # print_lsstring = result_display.when_type(LSString)(print_lsstring) class SList(list): """List derivative with a special access attributes. These are normal lists, but with the special attributes: * .l (or .list) : value as list (the list itself). * .n (or .nlstr): value as a string, joined on newlines. * .s (or .spstr): value as a string, joined on spaces. * .p (or .paths): list of path objects (requires path.py package) Any values which require transformations are computed only once and cached.""" def get_list(self): return self l = list = property(get_list) def get_spstr(self): try: return self.__spstr except AttributeError: self.__spstr = ' '.join(self) return self.__spstr s = spstr = property(get_spstr) def get_nlstr(self): try: return self.__nlstr except AttributeError: self.__nlstr = '\n'.join(self) return self.__nlstr n = nlstr = property(get_nlstr) def get_paths(self): from path import path try: return self.__paths except AttributeError: self.__paths = [path(p) for p in self if os.path.exists(p)] return self.__paths p = paths = property(get_paths) def grep(self, pattern, prune = False, field = None): """ Return all strings matching 'pattern' (a regex or callable) This is case-insensitive. If prune is true, return all items NOT matching the pattern. If field is specified, the match must occur in the specified whitespace-separated field. Examples:: a.grep( lambda x: x.startswith('C') ) a.grep('Cha.*log', prune=1) a.grep('chm', field=-1) """ def match_target(s): if field is None: return s parts = s.split() try: tgt = parts[field] return tgt except IndexError: return "" if isinstance(pattern, py3compat.string_types): pred = lambda x : re.search(pattern, x, re.IGNORECASE) else: pred = pattern if not prune: return SList([el for el in self if pred(match_target(el))]) else: return SList([el for el in self if not pred(match_target(el))]) def fields(self, *fields): """ Collect whitespace-separated fields from string list Allows quick awk-like usage of string lists. Example data (in var a, created by 'a = !ls -l'):: -rwxrwxrwx 1 ville None 18 Dec 14 2006 ChangeLog drwxrwxrwx+ 6 ville None 0 Oct 24 18:05 IPython * ``a.fields(0)`` is ``['-rwxrwxrwx', 'drwxrwxrwx+']`` * ``a.fields(1,0)`` is ``['1 -rwxrwxrwx', '6 drwxrwxrwx+']`` (note the joining by space). * ``a.fields(-1)`` is ``['ChangeLog', 'IPython']`` IndexErrors are ignored. Without args, fields() just split()'s the strings. """ if len(fields) == 0: return [el.split() for el in self] res = SList() for el in [f.split() for f in self]: lineparts = [] for fd in fields: try: lineparts.append(el[fd]) except IndexError: pass if lineparts: res.append(" ".join(lineparts)) return res def sort(self,field= None, nums = False): """ sort by specified fields (see fields()) Example:: a.sort(1, nums = True) Sorts a by second field, in numerical order (so that 21 > 3) """ #decorate, sort, undecorate if field is not None: dsu = [[SList([line]).fields(field), line] for line in self] else: dsu = [[line, line] for line in self] if nums: for i in range(len(dsu)): numstr = "".join([ch for ch in dsu[i][0] if ch.isdigit()]) try: n = int(numstr) except ValueError: n = 0; dsu[i][0] = n dsu.sort() return SList([t[1] for t in dsu]) # FIXME: We need to reimplement type specific displayhook and then add this # back as a custom printer. This should also be moved outside utils into the # core. # def print_slist(arg): # """ Prettier (non-repr-like) and more informative printer for SList """ # print "SList (.p, .n, .l, .s, .grep(), .fields(), sort() available):" # if hasattr(arg, 'hideonce') and arg.hideonce: # arg.hideonce = False # return # # nlprint(arg) # This was a nested list printer, now removed. # # print_slist = result_display.when_type(SList)(print_slist) def indent(instr,nspaces=4, ntabs=0, flatten=False): """Indent a string a given number of spaces or tabstops. indent(str,nspaces=4,ntabs=0) -> indent str by ntabs+nspaces. Parameters ---------- instr : basestring The string to be indented. nspaces : int (default: 4) The number of spaces to be indented. ntabs : int (default: 0) The number of tabs to be indented. flatten : bool (default: False) Whether to scrub existing indentation. If True, all lines will be aligned to the same indentation. If False, existing indentation will be strictly increased. Returns ------- str|unicode : string indented by ntabs and nspaces. """ if instr is None: return ind = '\t'*ntabs+' '*nspaces if flatten: pat = re.compile(r'^\s*', re.MULTILINE) else: pat = re.compile(r'^', re.MULTILINE) outstr = re.sub(pat, ind, instr) if outstr.endswith(os.linesep+ind): return outstr[:-len(ind)] else: return outstr def list_strings(arg): """Always return a list of strings, given a string or list of strings as input. Examples -------- :: In [7]: list_strings('A single string') Out[7]: ['A single string'] In [8]: list_strings(['A single string in a list']) Out[8]: ['A single string in a list'] In [9]: list_strings(['A','list','of','strings']) Out[9]: ['A', 'list', 'of', 'strings'] """ if isinstance(arg, py3compat.string_types): return [arg] else: return arg def marquee(txt='',width=78,mark='*'): """Return the input string centered in a 'marquee'. Examples -------- :: In [16]: marquee('A test',40) Out[16]: '**************** A test ****************' In [17]: marquee('A test',40,'-') Out[17]: '---------------- A test ----------------' In [18]: marquee('A test',40,' ') Out[18]: ' A test ' """ if not txt: return (mark*width)[:width] nmark = (width-len(txt)-2)//len(mark)//2 if nmark < 0: nmark =0 marks = mark*nmark return '%s %s %s' % (marks,txt,marks) ini_spaces_re = re.compile(r'^(\s+)') def num_ini_spaces(strng): """Return the number of initial spaces in a string""" ini_spaces = ini_spaces_re.match(strng) if ini_spaces: return ini_spaces.end() else: return 0 def format_screen(strng): """Format a string for screen printing. This removes some latex-type format codes.""" # Paragraph continue par_re = re.compile(r'\\$',re.MULTILINE) strng = par_re.sub('',strng) return strng def dedent(text): """Equivalent of textwrap.dedent that ignores unindented first line. This means it will still dedent strings like: '''foo is a bar ''' For use in wrap_paragraphs. """ if text.startswith('\n'): # text starts with blank line, don't ignore the first line return textwrap.dedent(text) # split first line splits = text.split('\n',1) if len(splits) == 1: # only one line return textwrap.dedent(text) first, rest = splits # dedent everything but the first line rest = textwrap.dedent(rest) return '\n'.join([first, rest]) def wrap_paragraphs(text, ncols=80): """Wrap multiple paragraphs to fit a specified width. This is equivalent to textwrap.wrap, but with support for multiple paragraphs, as separated by empty lines. Returns ------- list of complete paragraphs, wrapped to fill `ncols` columns. """ paragraph_re = re.compile(r'\n(\s*\n)+', re.MULTILINE) text = dedent(text).strip() paragraphs = paragraph_re.split(text)[::2] # every other entry is space out_ps = [] indent_re = re.compile(r'\n\s+', re.MULTILINE) for p in paragraphs: # presume indentation that survives dedent is meaningful formatting, # so don't fill unless text is flush. if indent_re.search(p) is None: # wrap paragraph p = textwrap.fill(p, ncols) out_ps.append(p) return out_ps def long_substr(data): """Return the longest common substring in a list of strings. Credit: http://stackoverflow.com/questions/2892931/longest-common-substring-from-more-than-two-strings-python """ substr = '' if len(data) > 1 and len(data[0]) > 0: for i in range(len(data[0])): for j in range(len(data[0])-i+1): if j > len(substr) and all(data[0][i:i+j] in x for x in data): substr = data[0][i:i+j] elif len(data) == 1: substr = data[0] return substr def strip_email_quotes(text): """Strip leading email quotation characters ('>'). Removes any combination of leading '>' interspersed with whitespace that appears *identically* in all lines of the input text. Parameters ---------- text : str Examples -------- Simple uses:: In [2]: strip_email_quotes('> > text') Out[2]: 'text' In [3]: strip_email_quotes('> > text\\n> > more') Out[3]: 'text\\nmore' Note how only the common prefix that appears in all lines is stripped:: In [4]: strip_email_quotes('> > text\\n> > more\\n> more...') Out[4]: '> text\\n> more\\nmore...' So if any line has no quote marks ('>') , then none are stripped from any of them :: In [5]: strip_email_quotes('> > text\\n> > more\\nlast different') Out[5]: '> > text\\n> > more\\nlast different' """ lines = text.splitlines() matches = set() for line in lines: prefix = re.match(r'^(\s*>[ >]*)', line) if prefix: matches.add(prefix.group(1)) else: break else: prefix = long_substr(list(matches)) if prefix: strip = len(prefix) text = '\n'.join([ ln[strip:] for ln in lines]) return text def strip_ansi(source): """ Remove ansi escape codes from text. Parameters ---------- source : str Source to remove the ansi from """ return re.sub(r'\033\[(\d|;)+?m', '', source) class EvalFormatter(Formatter): """A String Formatter that allows evaluation of simple expressions. Note that this version interprets a : as specifying a format string (as per standard string formatting), so if slicing is required, you must explicitly create a slice. This is to be used in templating cases, such as the parallel batch script templates, where simple arithmetic on arguments is useful. Examples -------- :: In [1]: f = EvalFormatter() In [2]: f.format('{n//4}', n=8) Out[2]: '2' In [3]: f.format("{greeting[slice(2,4)]}", greeting="Hello") Out[3]: 'll' """ def get_field(self, name, args, kwargs): v = eval(name, kwargs) return v, name #XXX: As of Python 3.4, the format string parsing no longer splits on a colon # inside [], so EvalFormatter can handle slicing. Once we only support 3.4 and # above, it should be possible to remove FullEvalFormatter. @skip_doctest_py3 class FullEvalFormatter(Formatter): """A String Formatter that allows evaluation of simple expressions. Any time a format key is not found in the kwargs, it will be tried as an expression in the kwargs namespace. Note that this version allows slicing using [1:2], so you cannot specify a format string. Use :class:`EvalFormatter` to permit format strings. Examples -------- :: In [1]: f = FullEvalFormatter() In [2]: f.format('{n//4}', n=8) Out[2]: u'2' In [3]: f.format('{list(range(5))[2:4]}') Out[3]: u'[2, 3]' In [4]: f.format('{3*2}') Out[4]: u'6' """ # copied from Formatter._vformat with minor changes to allow eval # and replace the format_spec code with slicing def _vformat(self, format_string, args, kwargs, used_args, recursion_depth): if recursion_depth < 0: raise ValueError('Max string recursion exceeded') result = [] for literal_text, field_name, format_spec, conversion in \ self.parse(format_string): # output the literal text if literal_text: result.append(literal_text) # if there's a field, output it if field_name is not None: # this is some markup, find the object and do # the formatting if format_spec: # override format spec, to allow slicing: field_name = ':'.join([field_name, format_spec]) # eval the contents of the field for the object # to be formatted obj = eval(field_name, kwargs) # do any conversion on the resulting object obj = self.convert_field(obj, conversion) # format the object and append to the result result.append(self.format_field(obj, '')) return u''.join(py3compat.cast_unicode(s) for s in result) @skip_doctest_py3 class DollarFormatter(FullEvalFormatter): """Formatter allowing Itpl style $foo replacement, for names and attribute access only. Standard {foo} replacement also works, and allows full evaluation of its arguments. Examples -------- :: In [1]: f = DollarFormatter() In [2]: f.format('{n//4}', n=8) Out[2]: u'2' In [3]: f.format('23 * 76 is $result', result=23*76) Out[3]: u'23 * 76 is 1748' In [4]: f.format('$a or {b}', a=1, b=2) Out[4]: u'1 or 2' """ _dollar_pattern = re.compile("(.*?)\$(\$?[\w\.]+)") def parse(self, fmt_string): for literal_txt, field_name, format_spec, conversion \ in Formatter.parse(self, fmt_string): # Find $foo patterns in the literal text. continue_from = 0 txt = "" for m in self._dollar_pattern.finditer(literal_txt): new_txt, new_field = m.group(1,2) # $$foo --> $foo if new_field.startswith("$"): txt += new_txt + new_field else: yield (txt + new_txt, new_field, "", None) txt = "" continue_from = m.end() # Re-yield the {foo} style pattern yield (txt + literal_txt[continue_from:], field_name, format_spec, conversion) #----------------------------------------------------------------------------- # Utils to columnize a list of string #----------------------------------------------------------------------------- def _col_chunks(l, nrows, row_first=False): """Yield successive nrows-sized column chunks from l.""" if row_first: ncols = (len(l) // nrows) + (len(l) % nrows > 0) for i in py3compat.xrange(ncols): yield [l[j] for j in py3compat.xrange(i, len(l), ncols)] else: for i in py3compat.xrange(0, len(l), nrows): yield l[i:(i + nrows)] def _find_optimal(rlist, row_first=False, separator_size=2, displaywidth=80): """Calculate optimal info to columnize a list of string""" for nrow in range(1, len(rlist) + 1): col_widths = list(map(max, _col_chunks(rlist, nrow, row_first))) sumlength = sum(col_widths) ncols = len(col_widths) if sumlength + separator_size * (ncols - 1) <= displaywidth: break return {'num_columns': ncols, 'optimal_separator_width': (displaywidth - sumlength) / (ncols - 1) if (ncols - 1) else 0, 'num_rows': nrow, 'column_widths': col_widths } def _get_or_default(mylist, i, default=None): """return list item number, or default if don't exist""" if i >= len(mylist): return default else : return mylist[i] def compute_item_matrix(items, row_first=False, empty=None, *args, **kwargs) : """Returns a nested list, and info to columnize items Parameters ---------- items list of strings to columize row_first : (default False) Whether to compute columns for a row-first matrix instead of column-first (default). empty : (default None) default value to fill list if needed separator_size : int (default=2) How much caracters will be used as a separation between each columns. displaywidth : int (default=80) The width of the area onto wich the columns should enter Returns ------- strings_matrix nested list of string, the outer most list contains as many list as rows, the innermost lists have each as many element as colums. If the total number of elements in `items` does not equal the product of rows*columns, the last element of some lists are filled with `None`. dict_info some info to make columnize easier: num_columns number of columns num_rows number of rows column_widths list of with of each columns optimal_separator_width best separator width between columns Examples -------- :: In [1]: l = ['aaa','b','cc','d','eeeee','f','g','h','i','j','k','l'] ...: compute_item_matrix(l, displaywidth=12) Out[1]: ([['aaa', 'f', 'k'], ['b', 'g', 'l'], ['cc', 'h', None], ['d', 'i', None], ['eeeee', 'j', None]], {'num_columns': 3, 'column_widths': [5, 1, 1], 'optimal_separator_width': 2, 'num_rows': 5}) """ info = _find_optimal(list(map(len, items)), row_first, *args, **kwargs) nrow, ncol = info['num_rows'], info['num_columns'] if row_first: return ([[_get_or_default(items, r * ncol + c, default=empty) for c in range(ncol)] for r in range(nrow)], info) else: return ([[_get_or_default(items, c * nrow + r, default=empty) for c in range(ncol)] for r in range(nrow)], info) def columnize(items, row_first=False, separator=' ', displaywidth=80): """ Transform a list of strings into a single string with columns. Parameters ---------- items : sequence of strings The strings to process. row_first : (default False) Whether to compute columns for a row-first matrix instead of column-first (default). separator : str, optional [default is two spaces] The string that separates columns. displaywidth : int, optional [default is 80] Width of the display in number of characters. Returns ------- The formatted string. """ if not items: return '\n' matrix, info = compute_item_matrix(items, row_first=row_first, separator_size=len(separator), displaywidth=displaywidth) fmatrix = [filter(None, x) for x in matrix] sjoin = lambda x : separator.join([ y.ljust(w, ' ') for y, w in zip(x, info['column_widths'])]) return '\n'.join(map(sjoin, fmatrix))+'\n' def get_text_list(list_, last_sep=' and ', sep=", ", wrap_item_with=""): """ Return a string with a natural enumeration of items >>> get_text_list(['a', 'b', 'c', 'd']) 'a, b, c and d' >>> get_text_list(['a', 'b', 'c'], ' or ') 'a, b or c' >>> get_text_list(['a', 'b', 'c'], ', ') 'a, b, c' >>> get_text_list(['a', 'b'], ' or ') 'a or b' >>> get_text_list(['a']) 'a' >>> get_text_list([]) '' >>> get_text_list(['a', 'b'], wrap_item_with="`") '`a` and `b`' >>> get_text_list(['a', 'b', 'c', 'd'], " = ", sep=" + ") 'a + b + c = d' """ if len(list_) == 0: return '' if wrap_item_with: list_ = ['%s%s%s' % (wrap_item_with, item, wrap_item_with) for item in list_] if len(list_) == 1: return list_[0] return '%s%s%s' % ( sep.join(i for i in list_[:-1]), last_sep, list_[-1])