String functions for Column operations
column_string_functions.Rd
String functions defined for Column
.
Usage
ascii(x)
base64(x)
bit_length(x, ...)
concat_ws(sep, x, ...)
decode(x, charset)
encode(x, charset)
format_number(y, x)
format_string(format, x, ...)
initcap(x)
instr(y, x)
levenshtein(y, x)
locate(substr, str, ...)
lower(x)
lpad(x, len, pad)
ltrim(x, trimString)
octet_length(x, ...)
overlay(x, replace, pos, ...)
regexp_extract(x, pattern, idx)
regexp_replace(x, pattern, replacement)
repeat_string(x, n)
rpad(x, len, pad)
rtrim(x, trimString)
split_string(x, pattern, ...)
soundex(x)
substring_index(x, delim, count)
translate(x, matchingString, replaceString)
trim(x, trimString)
unbase64(x)
upper(x)
# S4 method for Column
ascii(x)
# S4 method for Column
base64(x)
# S4 method for Column
bit_length(x)
# S4 method for Column,character
decode(x, charset)
# S4 method for Column,character
encode(x, charset)
# S4 method for Column
initcap(x)
# S4 method for Column
length(x)
# S4 method for Column
lower(x)
# S4 method for Column,missing
ltrim(x, trimString)
# S4 method for Column,character
ltrim(x, trimString)
# S4 method for Column
octet_length(x)
# S4 method for Column,Column,numericOrColumn
overlay(x, replace, pos, len = -1)
# S4 method for Column,missing
rtrim(x, trimString)
# S4 method for Column,character
rtrim(x, trimString)
# S4 method for Column
soundex(x)
# S4 method for Column,missing
trim(x, trimString)
# S4 method for Column,character
trim(x, trimString)
# S4 method for Column
unbase64(x)
# S4 method for Column
upper(x)
# S4 method for Column
levenshtein(y, x)
# S4 method for Column,character
instr(y, x)
# S4 method for Column,numeric
format_number(y, x)
# S4 method for character,Column
concat_ws(sep, x, ...)
# S4 method for character,Column
format_string(format, x, ...)
# S4 method for character,Column
locate(substr, str, pos = 1)
# S4 method for Column,numeric,character
lpad(x, len, pad)
# S4 method for Column,character,numeric
regexp_extract(x, pattern, idx)
# S4 method for Column,character,character
regexp_replace(x, pattern, replacement)
# S4 method for Column,numeric,character
rpad(x, len, pad)
# S4 method for Column,character,numeric
substring_index(x, delim, count)
# S4 method for Column,character,character
translate(x, matchingString, replaceString)
# S4 method for Column,character
split_string(x, pattern, limit = -1)
# S4 method for Column,numeric
repeat_string(x, n)
Arguments
- x
Column to compute on except in the following methods:
instr
:character
, the substring to check. See 'Details'.format_number
:numeric
, the number of decimal place to format to. See 'Details'.
- ...
additional Columns.
- sep
separator to use.
- charset
character set to use (one of "US-ASCII", "ISO-8859-1", "UTF-8", "UTF-16BE", "UTF-16LE", "UTF-16").
- y
Column to compute on.
- format
a character object of format strings.
- substr
a character string to be matched.
- str
a Column where matches are sought for each entry.
- len
In
lpad
the maximum length of each output result.overlay
a number of bytes to replace.
- pad
a character string to be padded with.
- trimString
a character string to trim with
- replace
a Column with replacement.
- pos
In
locate
: a start position of search.overlay
: a start position for replacement.
- pattern
a regular expression.
- idx
a group index.
- replacement
a character string that a matched
pattern
is replaced with.- n
number of repetitions.
- delim
a delimiter string.
- count
number of occurrences of
delim
before the substring is returned. A positive number means counting from the left, while negative means counting from the right.- matchingString
a source string where each character will be translated.
- replaceString
a target string where each
matchingString
character will be replaced by the character inreplaceString
at the same location, if any.- limit
determines the length of the returned array.
limit > 0
: length of the array will be at mostlimit
limit <= 0
: the returned array can have any length
Details
ascii
: Computes the numeric value of the first character of the string column,
and returns the result as an int column.
base64
: Computes the BASE64 encoding of a binary column and returns it as
a string column. This is the reverse of unbase64.
bit_length
: Calculates the bit length for the specified string column.
decode
: Computes the first argument into a string from a binary using the provided
character set.
encode
: Computes the first argument into a binary from a string using the provided
character set.
initcap
: Returns a new string column by converting the first letter of
each word to uppercase. Words are delimited by whitespace. For example, "hello world"
will become "Hello World".
length
: Computes the character length of a string data or number of bytes
of a binary data. The length of string data includes the trailing spaces.
The length of binary data includes binary zeros.
lower
: Converts a string column to lower case.
ltrim
: Trims the spaces from left end for the specified string value. Optionally a
trimString
can be specified.
octet_length
: Calculates the byte length for the specified string column.
overlay
: Overlay the specified portion of x
with replace
,
starting from byte position pos
of src
and proceeding for
len
bytes.
rtrim
: Trims the spaces from right end for the specified string value. Optionally a
trimString
can be specified.
soundex
: Returns the soundex code for the specified expression.
trim
: Trims the spaces from both ends for the specified string column. Optionally a
trimString
can be specified.
unbase64
: Decodes a BASE64 encoded string column and returns it as a binary column.
This is the reverse of base64.
upper
: Converts a string column to upper case.
levenshtein
: Computes the Levenshtein distance of the two given string columns.
instr
: Locates the position of the first occurrence of a substring (x
)
in the given string column (y
). Returns null if either of the arguments are null.
Note: The position is not zero based, but 1 based index. Returns 0 if the substring
could not be found in the string column.
format_number
: Formats numeric column y
to a format like '#,###,###.##',
rounded to x
decimal places with HALF_EVEN round mode, and returns the result
as a string column.
If x
is 0, the result has no decimal point or fractional part.
If x
< 0, the result will be null.
concat_ws
: Concatenates multiple input string columns together into a single
string column, using the given separator.
format_string
: Formats the arguments in printf-style and returns the result
as a string column.
locate
: Locates the position of the first occurrence of substr.
Note: The position is not zero based, but 1 based index. Returns 0 if substr
could not be found in str.
lpad
: Left-padded with pad to a length of len.
regexp_extract
: Extracts a specific idx
group identified by a Java regex,
from the specified string column. If the regex did not match, or the specified group did
not match, an empty string is returned.
regexp_replace
: Replaces all substrings of the specified string value that
match regexp with rep.
rpad
: Right-padded with pad to a length of len.
substring_index
: Returns the substring from string (x
) before count
occurrences of the delimiter (delim
). If count
is positive, everything the left of
the final delimiter (counting from left) is returned. If count
is negative, every to the
right of the final delimiter (counting from the right) is returned. substring_index
performs a case-sensitive match when searching for the delimiter.
translate
: Translates any character in the src by a character in replaceString.
The characters in replaceString is corresponding to the characters in matchingString.
The translate will happen when any character in the string matching with the character
in the matchingString.
split_string
: Splits string on regular expression.
Equivalent to split
SQL function. Optionally a
limit
can be specified
repeat_string
: Repeats string n times.
Equivalent to repeat
SQL function.
Note
ascii since 1.5.0
base64 since 1.5.0
length since 3.3.0
decode since 1.6.0
encode since 1.6.0
initcap since 1.5.0
length since 1.5.0
lower since 1.4.0
ltrim since 1.5.0
ltrim(Column, character) since 2.3.0
length since 3.3.0
overlay since 3.0.0
rtrim since 1.5.0
rtrim(Column, character) since 2.3.0
soundex since 1.5.0
trim since 1.5.0
trim(Column, character) since 2.3.0
unbase64 since 1.5.0
upper since 1.4.0
levenshtein since 1.5.0
instr since 1.5.0
format_number since 1.5.0
concat_ws since 1.5.0
format_string since 1.5.0
locate since 1.5.0
lpad since 1.5.0
regexp_extract since 1.5.0
regexp_replace since 1.5.0
rpad since 1.5.0
substring_index since 1.5.0
translate since 1.5.0
split_string 2.3.0
repeat_string since 2.3.0
Examples
if (FALSE) {
# Dataframe used throughout this doc
df <- createDataFrame(as.data.frame(Titanic, stringsAsFactors = FALSE))}
if (FALSE) {
head(select(df, ascii(df$Class), ascii(df$Sex)))}
if (FALSE) {
tmp <- mutate(df, s1 = encode(df$Class, "UTF-8"))
str(tmp)
tmp2 <- mutate(tmp, s2 = base64(tmp$s1), s3 = decode(tmp$s1, "UTF-8"),
s4 = soundex(tmp$Sex))
head(tmp2)
head(select(tmp2, unbase64(tmp2$s2)))}
if (FALSE) {
tmp <- mutate(df, sex_lower = lower(df$Sex), age_upper = upper(df$age),
sex_age = concat_ws(" ", lower(df$sex), lower(df$age)))
head(tmp)
tmp2 <- mutate(tmp, s1 = initcap(tmp$sex_lower), s2 = initcap(tmp$sex_age),
s3 = reverse(df$Sex))
head(tmp2)}
if (FALSE) {
tmp <- mutate(df, SexLpad = lpad(df$Sex, 6, " "), SexRpad = rpad(df$Sex, 7, " "))
head(select(tmp, length(tmp$Sex), length(tmp$SexLpad), length(tmp$SexRpad)))
tmp2 <- mutate(tmp, SexLtrim = ltrim(tmp$SexLpad), SexRtrim = rtrim(tmp$SexRpad),
SexTrim = trim(tmp$SexLpad))
head(select(tmp2, length(tmp2$Sex), length(tmp2$SexLtrim),
length(tmp2$SexRtrim), length(tmp2$SexTrim)))
tmp <- mutate(df, SexLpad = lpad(df$Sex, 6, "xx"), SexRpad = rpad(df$Sex, 7, "xx"))
head(tmp)}
if (FALSE) {
tmp <- mutate(df, d1 = levenshtein(df$Class, df$Sex),
d2 = levenshtein(df$Age, df$Sex),
d3 = levenshtein(df$Age, df$Age))
head(tmp)}
if (FALSE) {
tmp <- mutate(df, s1 = instr(df$Sex, "m"), s2 = instr(df$Sex, "M"),
s3 = locate("m", df$Sex), s4 = locate("m", df$Sex, pos = 4))
head(tmp)}
if (FALSE) {
tmp <- mutate(df, v1 = df$Freq/3)
head(select(tmp, format_number(tmp$v1, 0), format_number(tmp$v1, 2),
format_string("%4.2f %s", tmp$v1, tmp$Sex)), 10)}
if (FALSE) {
# concatenate strings
tmp <- mutate(df, s1 = concat_ws("_", df$Class, df$Sex),
s2 = concat_ws("+", df$Class, df$Sex, df$Age, df$Survived))
head(tmp)}
if (FALSE) {
tmp <- mutate(df, s1 = regexp_extract(df$Class, "(\\d+)\\w+", 1),
s2 = regexp_extract(df$Sex, "^(\\w)\\w+", 1),
s3 = regexp_replace(df$Class, "\\D+", ""),
s4 = substring_index(df$Sex, "a", 1),
s5 = substring_index(df$Sex, "a", -1),
s6 = translate(df$Sex, "ale", ""),
s7 = translate(df$Sex, "a", "-"))
head(tmp)}
if (FALSE) {
head(select(df, split_string(df$Class, "\\d", 2)))
head(select(df, split_string(df$Sex, "a")))
head(select(df, split_string(df$Class, "\\d")))
# This is equivalent to the following SQL expression
head(selectExpr(df, "split(Class, '\\\\d')"))}
if (FALSE) {
head(select(df, repeat_string(df$Class, 3)))
# This is equivalent to the following SQL expression
head(selectExpr(df, "repeat(Class, 3)"))}