A fresh approach to string manipulation in R
Some minor documentation improvements.
str_trunc() now correctly truncates strings when side is "left" or
"center" (@UchidaMizuki, #512).
stringr functions now consistently implement the tidyverse recycling rules (#372). There are two main changes:
Only vectors of length 1 are recycled. Previously, (e.g.)
str_detect(letters, c("x", "y")) worked, but it now errors.
str_c() ignores NULLs, rather than treating them as length 0
vectors.
Additionally, many more arguments now throw errors, rather than warnings, if supplied the wrong type of input.
regex() and friends now generate class names with stringr_ prefix (#384).
str_detect(), str_starts(), str_ends() and str_subset() now error
when used with either an empty string ("") or a boundary(). These
operations didn't really make sense (str_detect(x, "") returned TRUE
for all non-empty strings) and made it easy to make mistakes when programming.
Many tweaks to the documentation to make it more useful and consistent.
New vignette("from-base") by @sastoudt provides a comprehensive comparison
between base R functions and their stringr equivalents. It's designed to
help you move to stringr if you're already familiar with base R string
functions (#266).
New str_escape() escapes regular expression metacharacters, providing
an alternative to fixed() if you want to compose a pattern from user
supplied strings (#408).
New str_equal() compares two character vectors using unicode rules,
optionally ignoring case (#381).
str_extract() can now optionally extract a capturing group instead of
the complete match (#420).
New str_flatten_comma() is a special case of str_flatten() designed for
comma separated flattening and can correctly apply the Oxford commas
when there are only two elements (#444).
New str_split_1() is tailored for the special case of splitting up a single
string (#409).
New str_split_i() extract a single piece from a string (#278, @bfgray3).
New str_like() allows the use of SQL wildcards (#280, @rjpat).
New str_rank() to complete the set of order/rank/sort functions (#353).
New str_sub_all() to extract multiple substrings from each string.
New str_unique() is a wrapper around stri_unique() and returns unique
string values in a character vector (#249, @seasmith).
str_view() uses ANSI colouring rather than an HTML widget (#370). This
works in more places and requires fewer dependencies. It includes a number
of other small improvements:
andpattern` (#407).str_view_all() redundant
(and hence deprecated) (#455).New str_width() returns the display width of a string (#380).
stringr is now licensed as MIT (#351).
Better error message if you supply a non-string pattern (#378).
A new data source for sentences has fixed many small errors.
str_extract() and str_exctract_all() now work correctly when pattern
is a boundary().
str_flatten() gains a last argument that optionally override the
final separator (#377). It gains a na.rm argument to remove missing
values (since it's a summary function) (#439).
str_pad() gains use_width argument to control whether to use the total
code point width or the number of code points as "width" of a string (#190).
str_replace() and str_replace_all() can use standard tidyverse formula
shorthand for replacement function (#331).
str_starts() and str_ends() now correctly respect regex operator
precedence (@carlganz).
str_wrap() breaks only at whitespace by default; set
whitespace_only = FALSE to return to the previous behaviour (#335, @rjpat).
word() now returns all the sentence when using a negative start parameter
that is greater or equal than the number of words. (@pdelboca, #245)
Hot patch release to resolve R CMD check failures.
str_interp() now renders lists consistently independent on the presence of
additional placeholders (@amhrasmussen).
New str_starts() and str_ends() functions to detect patterns at the
beginning or end of strings (@jonthegeek, #258).
str_subset(), str_detect(), and str_which() get negate argument,
which is useful when you want the elements that do NOT match (#259,
@yutannihilation).
New str_to_sentence() function to capitalize with sentence case
(@jonthegeek, #202).
str_replace_all() with a named vector now respects modifier functions (#207)
str_trunc() is once again vectorised correctly (#203, @austin3dickey).
str_view() handles NA values more gracefully (#217). I've also
tweaked the sizing policy so hopefully it should work better in notebooks,
while preserving the existing behaviour in knit documents (#232).
Error : object ‘ignore.case’ is not exported by 'namespace:stringr'.
This is because the long deprecated str_join(), ignore.case() and
perl() have now been removed.str_glue() and str_glue_data() provide convenient wrappers around
glue and glue_data() from the glue package
(#157).
str_flatten() is a wrapper around stri_flatten() and clearly
conveys flattening a character vector into a single string (#186).
str_remove() and str_remove_all() functions. These wrap
str_replace() and str_replace_all() to remove patterns from strings.
(@Shians, #178)
str_squish() removes spaces from both the left and right side of strings,
and also converts multiple space (or space-like characters) to a single
space within strings (@stephlocke, #197).
str_sub() gains omit_na argument for ignoring NA. Accordingly,
str_replace() now ignores NAs and keeps the original strings.
(@yutannihilation, #164)
str_trunc() now preserves NAs (@ClaytonJY, #162)
str_trunc() now throws an error when width is shorter than ellipsis
(@ClaytonJY, #163).
Long deprecated str_join(), ignore.case() and perl() have now been
removed.
str_match_all() now returns NA if an optional group doesn't match
(previously it returned ""). This is more consistent with str_match()
and other match failures (#134).str_replace(), replacement can now be a function that is called once
for each match and who's return value is used to replace the match.str_which() mimics grep() (#129).vignette("regular-expressions")) describes the
details of the regular expressions supported by stringr.
The main vignette (vignette("stringr")) has been updated to
give a high-level overview of the package.str_order() and str_sort() gain explicit numeric argument for sorting
mixed numbers and strings.str_replace_all() now throws an error if replacement is not a character
vector. If replacement is NA_character_ it replaces the complete string
with replaces with NA (#124).str_to_lower() and str_sort())
default to "en" (English) to ensure that the default is consistent across
platforms.fruit, words and sentences.fixed(), regex(), and coll() now throw an error if you use them with
anything other than a plain string (#60). I've clarified that the replacement
for perl() is regex() not regexp() (#61). boundary() has improved
defaults when splitting on non-word boundaries (#58, @lmullen).str_detect() now can detect boundaries (by checking for a str_count() > 0)
(#120). str_subset() works similarly.str_extract() and str_extract_all() now work with boundary(). This is
particularly useful if you want to extract logical constructs like words
or sentences. str_extract_all() respects the simplify argument
when used with fixed() matches.str_subset() now respects custom options for fixed() patterns
(#79, @gagolews).str_replace() and str_replace_all() now behave correctly when a
replacement string contains $s, \\\\1, etc. (#83, #99).str_split() gains a simplify argument to match str_extract_all()
etc.str_view() and str_view_all() create HTML widgets that display regular
expression matches (#96).word() returns NA for indexes greater than number of words (#112).stringr is now powered by stringi instead of base R regular expressions. This improves unicode and support, and makes most operations considerably faster. If you find stringr inadequate for your string processing needs, I highly recommend looking at stringi in more detail.
stringr gains a vignette, currently a straight forward update of the article that appeared in the R Journal.
str_c() now returns a zero length vector if any of its inputs are zero length vectors. This is consistent with all other functions, and standard R recycling rules. Similarly, using str_c("x", NA) now yields NA. If you want "xNA", use str_replace_na() on the inputs.
str_replace_all() gains a convenient syntax for applying multiple pairs of pattern and replacement to the same vector:
input <- c("abc", "def")
str_replace_all(input, c("[ad]" = "!", "[cf]" = "?"))
str_match() now returns NA if an optional group doesn't match (previously it returned ""). This is more consistent with str_extract() and other match failures.
New str_subset() keeps values that match a pattern. It's a convenient wrapper for x[str_detect(x)] (#21, @jiho).
New str_order() and str_sort() allow you to sort and order strings in a specified locale.
New str_conv() to convert strings from specified encoding to UTF-8.
New modifier boundary() allows you to count, locate and split by character, word, line and sentence boundaries.
The documentation got a lot of love, and very similar functions (e.g. first and all variants) are now documented together. This should hopefully make it easier to locate the function you need.
ignore.case(x) has been deprecated in favour of fixed|regexp|coll(x, ignore.case = TRUE), perl(x) has been deprecated in favour of regexp(x).
str_join() is deprecated, please use str_c() instead.