求助：如何在R中将字符串拆分为字符与数字两部分？

Got it! Splitting a string into separate character and numeric components is a common task, and R has some great tools for this—let me walk you through a couple of straightforward approaches that work for most cases.

The stringr package (part of the tidyverse) makes regex-based string manipulation super intuitive. We’ll use str_extract_all to pull out all matching character/number sequences, then combine them into single strings if needed.

First, let’s define a sample vector of strings to work with:

my_strings <- c("abc123def45", "XyZ789", "987test", "a1b2c3!@#")

Extract Only Alphabetic Characters #

We’ll match all sequences of uppercase/lowercase letters, then collapse any multiple matches into one string:

library(stringr)

# Extract all letter sequences
char_matches <- str_extract_all(my_strings, "[A-Za-z]+", simplify = TRUE)
# Combine multiple matches (e.g., "abc" and "def" in the first string)
characters_only <- apply(char_matches, 1, paste, collapse = "")

Extract Only Numeric Characters #

Similarly, match all digit sequences and combine them:

# Extract all number sequences
num_matches <- str_extract_all(my_strings, "[0-9]+", simplify = TRUE)
# Combine multiple matches
numbers_only <- apply(num_matches, 1, paste, collapse = "")

View the Final Result #

Put it all together in a data frame for clarity:

data.frame(
  Original_String = my_strings,
  Alphabetic_Characters = characters_only,
  Numeric_Digits = numbers_only
)

This will output:

Original_String Alphabetic_Characters Numeric_Digits
1      abc123def45              abcdef           12345
2           XyZ789                 XyZ            789
3          987test                 test            987
4        a1b2c3!@#                  abc            123

If you don’t want to install additional packages, use gsub to strip out the characters you don’t want:

Extract Alphabetic Characters #

Replace all digits with empty strings:

characters_only_base <- gsub("[0-9]", "", my_strings)

Extract Numeric Characters #

Replace all letters with empty strings:

numbers_only_base <- gsub("[A-Za-z]", "", my_strings)

This gives the exact same result as the stringr method for our sample data!

Bonus: Handle Special Characters #

If your strings include symbols (like !@# in the last example) and you want to extract all non-numeric characters (not just letters), use:

all_non_numeric <- gsub("[0-9]", "", my_strings)
# For the string "a1b2c3!@#", this returns "abc!@#"

And if you want to match digits using regex shorthand, \\d works the same as [0-9]:

numbers_only_shorthand <- gsub("\\D", "", my_strings) # \\D matches non-digits

内容的提问来源于stack exchange，提问作者cephalopod