如何在 Golang 使用 Regex 拆分文本？
原文:https://www . geeksforgeeks . org/如何使用-regex-in-golang/ 拆分文本
什么是正则表达式？Regex 是著名的动漫角色吗？哎呀，如果你这样想，你可能会失望。围棋编程语言使用术语正则表达式来表示 正则表达式。正则表达式在字符串处理领域非常重要。Go 中的“【regexp】**”包保存了所有必要的预构建函数，这些函数实现了正则表达式搜索，并保证了所提供输入大小的线性时间搜索。想了解更多什么是 regex，请阅读 在 Golang 什么是 Regexp？
如何使用正则表达式(或 regex)拆分输入文本？
Regexp 包包含有助于分割输入文本字符串的分割函数。在我们深入 regexp split 函数之前，让我们向您简要介绍一些在使用 split 函数时值得记住的基本正则表达式:
| [Character] | What does it mean? | Example grammar | 正则表达式的结果 | | --- | --- | --- | --- | | [] | []可用于包含或 排除给定范围，甚至 专门提到我们想要包含或排除的字符 。 [ ]表示在一个范围内包括两者。 | “【B- f】an” | ban、can、dan、 ean、fan | | { } | 当 一个人需要匹配任意给定 表达式出现的频率 时，就会用到花括号。 | “gf { 1，} g” | gfg、gffg、gfffg、…… | | ) | () can be used to include or exclude a given range, and even specifically mentions that we want the character () to represent the capture group with number. | ”(B- f)an“ | ban、can、dan、 ean、fan | | * | *匹配位于 星之前的字符的 0/0+出现次数 (*)。 | “gee * k” | 盖奇奇奇… | | + | +匹配位于 加号(“+”)之前的字符的 1/1+出现次数 。 | 【gee+k】 | geek、…… | | ？ | ? Match question mark ('?' 0-1 times of the previous character ). | “啧啧？k" | gek，geek | | 。 | 除了换行符(\n)之外，任何东西都可以代替点 字符。 | 【g . g】 | gfg、gbg、gcg、…… | | ^ | 任何以'^'.之后提到的字符串 开头的文本也用作组内否定 或其他正则表达式(NOT)。 | 【^ge】【^0-8]*】 | ge、geek、geek、… | | $ | It indicates that the string is in a | “$ de” | 编码、解码、…… | | | | | is the or operator. | [geek | principle] | Geek, geek, principle, principle .. | | \ | This is the escape character . If you need to mention what likes "\s", then you need to use "\\s", so that the system can understand that it is "\s". | " \ A " " \ \ n " " \ \ s " 等.. | | | \ S | Select all spaces only. | “\ \ S” | “，”、“，…… | | 2、3、4、5、 6、7、8、9 | | \ D | Extract all text except numbers. | " \ \ D " | |语法:
***func*** Split(s: string, n: int) []string
该函数接受一个字符串和一个整数，并返回所有子字符串的一部分。输入字符串“ s 是将被进一步分割的字符串，根据分割函数给出的正则表达式分割为子字符串。 n 表示决定要返回的子字符串数量的值。
- 如果 n > 0 :表示最多有 n 个子串经过正则化运算，将被返回。
- 如果 n = 1 ，则不会执行正则表达式操作，因此将返回原始字符串。
- 如果 n = 0 :表示不返回子串，返回一个 nill。
- 如果 n < 0 :这意味着所有创建的子字符串都将被函数返回。
例 1:
去
package main
import (
f "fmt"
re "regexp"
// we import the regexp package
// as re
)
// SPLIT function hacks
// In layman terms, whenever the
// string (given to split as argument)
// occurs, the string is split into
// a substring.
func main() {
// str stores a sample string as shown below
str := "I am at GFG!\nYou can call me at 9087651234."
// just printing the original string: str
f.Println(str)
// We shall consider two scenarios
// in this example code
// Scenario 1:
// Store a regex object that
// contains digits only
// in obj1.
obj1 := re.MustCompile("\\d*")
// Scenario 2:
// Store a regex object that
// contains everything except digits
// in obj2.
obj2 := re.MustCompile("\\D*")
// Using obj1 as reference, we
// are splitting the string: str
// and -1 denotes that all substrings
// ever created will be included.
first := obj1.Split(str, -1)
// "first" holds all the substrings
// split from str w.r.t obj1 in a container
// A container like, say a list.
// Using obj2 as reference, we
// are splitting the string: str
// and -1 denotes that all substrings
// ever created will be included.
second := obj2.Split(str, -1)
// "second" holds all the substrings
// split from str w.r.t obj2 in a container
// A container like, say a list.
f.Println("Now printing text split by obj1...")
for _, p := range first {
f.Println(p)
}
f.Println("Now printing text split by obj2...")
for _, q := range second {
f.Println(q)
}
}
要执行的命令:
> go run (your_file_name).go
输出:
I am at GFG!
You can call me at 9087651234.
Now printing text split by obj1...
I
a
m
a
t
G
F
G
!
Y
o
u
c
a
n
c
a
l
l
m
e
a
t
.
Now printing text split by obj2...
9
0
8
7
6
5
1
2
3
4
Visual Studio 代码上的可视化 I/O 演示:
运行上面编写的代码时，屏幕上的代码输出。
例 2:
去
package main
import (
f "fmt"
re "regexp"
)
// Simple example code to understand
// 1\. Function of Split function
// 2\. Parameters of split function
// regex-object.Split(string: , n: )
func main() {
// Sample string that will be used in this
// example "GeeksforGeeks loves bananas"
str := "GeeksforGeeks loves bananas"
f.Println(str)
f.Println("Part-1: Excluding all vowels from given string")
// a regexp object (geek) for storing all vowels
geek := re.MustCompile("[aeiou]")
f.Print("Printing all substring lists = ")
// Checking split for n = -1
f.Println(geek.Split(str, -1))
f.Print("For n = 0 substring list = ")
// Checking split for n = 0
f.Println(geek.Split(str, 0))
f.Print("For n = 1 substring list = ")
// Checking split for n = 1
f.Println(geek.Split(str, 1))
f.Print("For n = 10 substring list = ")
// Checking split for n = 10
f.Println(geek.Split(str, 10))
f.Print("For n = 100 substring list = ")
// Checking split for n = 100
f.Println(geek.Split(str, 100))
f.Println("\n\nPart-2: Extracting all vowels from given string")
// a regexp object (geek) for storing all consonants
geek = re.MustCompile("[^aeiou]")
f.Print("Printing all substring lists = ")
// Checking split for n = -1
f.Println(geek.Split(str, -1))
f.Print("For n = 0 substring list = ")
// Checking split for n = 0
f.Println(geek.Split(str, 0))
f.Print("For n = 1 substring list = ")
// Checking split for n = 1
f.Println(geek.Split(str, 1))
f.Print("For n = 10 substring list = ")
// Checking split for n = 10
f.Println(geek.Split(str, 10))
f.Print("For n = 100 substring list = ")
// Checking split for n = 100
f.Println(geek.Split(str, 100))
// Did you notice that split function
// does not modify the original regex
// matching object?
}
要执行的命令:
> go run (your_file_name).go
输出:
GeeksforGeeks loves bananas
Part-1: Excluding all vowels from given string
Printing all substring lists = [G ksf rG ks l v s b n n s]
For n = 0 substring list = []
For n = 1 substring list = [GeeksforGeeks loves bananas]
For n = 10 substring list = [G ksf rG ks l v s b n nas]
For n = 100 substring list = [G ksf rG ks l v s b n n s]
Part-2: Extracting all vowels from given string
Printing all substring lists = [ ee o ee o e a a a ]
For n = 0 substring list = []
For n = 1 substring list = [GeeksforGeeks loves bananas]
For n = 10 substring list = [ ee o ee loves bananas]
For n = 100 substring list = [ ee o ee o e a a a ]
Visual Studio 代码上的可视化 I/O 演示:
运行上面编写的代码时，屏幕上的代码输出。
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