用文本文件中的字符串替换数字

Question

Given a string as input, I want to find and convert the integer elements of the line with the string num . Here is an example:

input:

"abc 123 def 1 in 1s and 100MB"

output:

"abc >num< def >num< in 1s and 100MB"

How can I do it?

Answer 1

That is how.

text_in = "abc 123 def 1 in 1s and 100MB"
text_out = ' '.join(['>num<' if x.isnumeric() else x for x in text_in.split()])
print(text_out)  # prints: abc >num< def >num< in 1s and 100MB

I took the liberty to assume that you can read the text from a file and can also write the new text to a file so I am skipping those parts.

It all boils down to the use of isnumeric() .

Answer 2

Use a regular expression :

import re

s = "abc 123 def 1 in 1s and 100MB"

print(re.sub(r"\b\d+\b", ">num<", s))
# output: "abc >num< def >num< in 1s and 100MB"

The regular expression string r"\\b\\d+\\b" matches a character string that consists of at least one numeral character ( \\d+ ) enclosed by word boundaries ( \\b ). The \\b part also matches the beginning and the end of a string.

The call to re.sub() replaces all occurrences of a matching character string in the third argument s by the second argument ( ">num<" ).