release v1.3.3

README.md

@@ -4,7 +4,7 @@
 <br/>
 
 ![Go version](https://img.shields.io/badge/go-v1.16-9cf)
-[![Release](https://img.shields.io/badge/release-1.3.2-green.svg)](https://github.com/duke-git/lancet/releases)
+[![Release](https://img.shields.io/badge/release-1.3.3-green.svg)](https://github.com/duke-git/lancet/releases)
 [![GoDoc](https://godoc.org/github.com//duke-git/lancet?status.svg)](https://pkg.go.dev/github.com/duke-git/lancet)
 [![Go Report Card](https://goreportcard.com/badge/github.com/duke-git/lancet)](https://goreportcard.com/report/github.com/duke-git/lancet)
 [![test](https://github.com/duke-git/lancet/actions/workflows/codecov.yml/badge.svg?branch=main&event=push)](https://github.com/duke-git/lancet/actions/workflows/codecov.yml)
@@ -62,12 +62,15 @@ func main() {
 ```
 
 ## API Documentation
+
 ### 1. Convertor package contains some functions for data convertion.
 
 ```go
 import "github.com/duke-git/lancet/convertor"
 ```
+
 #### Function list:
+
 -   [ColorHexToRGB](https://github.com/duke-git/lancet/blob/v1/docs/convertor.md#ColorHexToRGB)
 -   [ColorRGBToHex](https://github.com/duke-git/lancet/blob/v1/docs/convertor.md#ColorRGBToHex)
 -   [ToBool](https://github.com/duke-git/lancet/blob/v1/docs/convertor.md#ToBool)
@@ -88,6 +91,7 @@ import "github.com/duke-git/lancet/cryptor"
 ```
 
 #### Function list:
+
 -   [AesEcbEncrypt](https://github.com/duke-git/lancet/blob/v1/docs/cryptor.md#AesEcbEncrypt)
 -   [AesEcbDecrypt](https://github.com/duke-git/lancet/blob/v1/docs/cryptor.md#AesEcbDecrypt)
 -   [AesCbcEncrypt](https://github.com/duke-git/lancet/blob/v1/docs/cryptor.md#AesCbcEncrypt)
@@ -123,11 +127,12 @@ import "github.com/duke-git/lancet/cryptor"
 
 ### 3. Datetime package supports date and time format and compare.
 
-
 ```go
 import "github.com/duke-git/lancet/datetime"
 ```
+
 #### Function list:
+
 -   [AddDay](https://github.com/duke-git/lancet/blob/v1/docs/datetime.md#AddDay)
 -   [AddHour](https://github.com/duke-git/lancet/blob/v1/docs/datetime.md#AddHour)
 -   [AddMinute](https://github.com/duke-git/lancet/blob/v1/docs/datetime.md#AddMinute)
@@ -188,7 +193,9 @@ import "github.com/duke-git/lancet/fileutil"
 ```go
 import "github.com/duke-git/lancet/formatter"
 ```
+
 #### Function list:
+
 -   [Comma](https://github.com/duke-git/lancet/blob/v1/docs/formatter.md#Comma)
 
 ### Function package can control the flow of function execution and support part of functional programming
@@ -198,6 +205,7 @@ import "github.com/duke-git/lancet/function"
 ```
 
 #### Function list:
+
 -   [After](https://github.com/duke-git/lancet/blob/v1/docs/function.md#After)
 -   [Before](https://github.com/duke-git/lancet/blob/v1/docs/function.md#Before)
 -   [Curry](https://github.com/duke-git/lancet/blob/v1/docs/function.md#Curry)
@@ -206,7 +214,6 @@ import "github.com/duke-git/lancet/function"
 -   [Delay](https://github.com/duke-git/lancet/blob/v1/docs/function.md#Delay)
 -   [Watcher](https://github.com/duke-git/lancet/blob/v1/docs/function.md#Watcher)
 
-
 ### 6. Mathutil package implements some functions for math calculation.
 
 ```go
@@ -214,6 +221,7 @@ import "github.com/duke-git/lancet/mathutil"
 ```
 
 #### Function list:
+
 -   [Exponent](https://github.com/duke-git/lancet/blob/v1/docs/mathutil.md#Exponent)
 -   [Fibonacci](https://github.com/duke-git/lancet/blob/v1/docs/mathutil.md#Fibonacci)
 -   [Factorial](https://github.com/duke-git/lancet/blob/v1/docs/mathutil.md#Factorial)
@@ -222,7 +230,6 @@ import "github.com/duke-git/lancet/mathutil"
 -   [RoundToString](https://github.com/duke-git/lancet/blob/v1/docs/mathutil.md#RoundToString)
 -   [TruncRound](https://github.com/duke-git/lancet/blob/v1/docs/mathutil.md#TruncRound)
 
-
 ### 7. Netutil package contains functions to get net information and send http request.
 
 ```go
@@ -230,6 +237,7 @@ import "github.com/duke-git/lancet/netutil"
 ```
 
 #### Function list:
+
 -   [ConvertMapToQueryString](https://github.com/duke-git/lancet/blob/v1/docs/netutil.md#ConvertMapToQueryString)
 -   [EncodeUrl](https://github.com/duke-git/lancet/blob/v1/docs/netutil.md#EncodeUrl)
 -   [GetInternalIp](https://github.com/duke-git/lancet/blob/v1/docs/netutil.md#GetInternalIp)
@@ -246,7 +254,6 @@ import "github.com/duke-git/lancet/netutil"
 -   [HttpPatch](https://github.com/duke-git/lancet/blob/v1/docs/netutil.md#HttpPatch)
 -   [ParseHttpResponse](https://github.com/duke-git/lancet/blob/v1/docs/netutil.md#ParseHttpResponse)
 
-
 ### 8. Random package implements some basic functions to generate random int and string.
 
 ```go
@@ -254,9 +261,14 @@ import "github.com/duke-git/lancet/random"
 ```
 
 #### Function list:
+
 -   [RandBytes](https://github.com/duke-git/lancet/blob/v1/docs/random.md#RandBytes)
 -   [RandInt](https://github.com/duke-git/lancet/blob/v1/docs/random.md#RandInt)
 -   [RandString](https://github.com/duke-git/lancet/blob/v1/docs/random.md#RandString)
+-   [RandUpper](https://github.com/duke-git/lancet/blob/v1/docs/random.md#RandUpper)
+-   [RandLower](https://github.com/duke-git/lancet/blob/v1/docs/random.md#RandLower)
+-   [RandNumeral](https://github.com/duke-git/lancet/blob/v1/docs/random.md#RandNumeral)
+-   [RandNumeralOrLetter](https://github.com/duke-git/lancet/blob/v1/docs/random.md#RandNumeralOrLetter)
 -   [UUIdV4](https://github.com/duke-git/lancet/blob/v1/docs/random.md#UUIdV4)
 
 ### 9. Retry package is for executing a function repeatedly until it was successful or canceled by the context.
@@ -266,6 +278,7 @@ import "github.com/duke-git/lancet/retry"
 ```
 
 #### Function list:
+
 -   [Context](https://github.com/duke-git/lancet/blob/v1/docs/retry.md#Context)
 -   [Retry](https://github.com/duke-git/lancet/blob/v1/docs/retry.md#Retry)
 -   [RetryFunc](https://github.com/duke-git/lancet/blob/v1/docs/retry.md#RetryFunc)
@@ -279,6 +292,7 @@ import "github.com/duke-git/lancet/slice"
 ```
 
 #### Function list:
+
 -   [AppendIfAbsent](https://github.com/duke-git/lancet/blob/v1/docs/slice.md#AppendIfAbsent)
 -   [Contain](https://github.com/duke-git/lancet/blob/v1/docs/slice.md#Contain)
 -   [ContainSubSlice](https://github.com/duke-git/lancet/blob/v1/docs/slice.md#ContainSubSlice)
@@ -353,6 +367,7 @@ import "github.com/duke-git/lancet/system"
 ```
 
 #### Function list:
+
 -   [IsWindows](https://github.com/duke-git/lancet/blob/v1/docs/system.md#IsWindows)
 -   [IsLinux](https://github.com/duke-git/lancet/blob/v1/docs/system.md#IsLinux)
 -   [IsMac](https://github.com/duke-git/lancet/blob/v1/docs/system.md#IsMac)
@@ -368,6 +383,7 @@ import "github.com/duke-git/lancet/system"
 ```go
 import "github.com/duke-git/lancet/validator"
 ```
+
 #### Function list:
 
 -   [ContainChinese](https://github.com/duke-git/lancet/blob/v1/docs/validator.md#ContainChinese)
@@ -398,7 +414,6 @@ import "github.com/duke-git/lancet/validator"
 -   [IsWeakPassword](https://github.com/duke-git/lancet/blob/v1/docs/validator.md#IsWeakPassword)
 -   [IsZeroValue](https://github.com/duke-git/lancet/blob/v1/docs/validator.md#IsZeroValue)
 
-
 ## How to Contribute
 
 I really appreciate any code commits which make lancet lib powerful. Please follow the rules below to create your pull request.

README_zh-CN.md

@@ -4,7 +4,7 @@
 <br/>
 
 ![Go version](https://img.shields.io/badge/go-v1.16-9cf)
-[![Release](https://img.shields.io/badge/release-1.3.2-green.svg)](https://github.com/duke-git/lancet/releases)
+[![Release](https://img.shields.io/badge/release-1.3.3-green.svg)](https://github.com/duke-git/lancet/releases)
 [![GoDoc](https://godoc.org/github.com//duke-git/lancet?status.svg)](https://pkg.go.dev/github.com/duke-git/lancet)
 [![Go Report Card](https://goreportcard.com/badge/github.com/duke-git/lancet)](https://goreportcard.com/report/github.com/duke-git/lancet)
 [![test](https://github.com/duke-git/lancet/actions/workflows/codecov.yml/badge.svg?branch=main&event=push)](https://github.com/duke-git/lancet/actions/workflows/codecov.yml)
@@ -20,7 +20,6 @@
 
 简体中文 | [English](./README.md)
 
-
 ## 特性
 
 -   👏 全面、高效、可复用
@@ -62,12 +61,15 @@ func main() {
 ```
 
 ## API 文档
+
 ### 1. convertor 转换器包支持一些常见的数据类型转换。
 
 ```go
 import "github.com/duke-git/lancet/convertor"
 ```
+
 #### 函数列表:
+
 -   [ColorHexToRGB](https://github.com/duke-git/lancet/blob/v1/docs/convertor_zh-CN.md#ColorHexToRGB)
 -   [ColorRGBToHex](https://github.com/duke-git/lancet/blob/v1/docs/convertor_zh-CN.md#ColorRGBToHex)
 -   [ToBool](https://github.com/duke-git/lancet/blob/v1/docs/convertor_zh-CN.md#ToBool)
@@ -88,6 +90,7 @@ import "github.com/duke-git/lancet/cryptor"
 ```
 
 #### 函数列表:
+
 -   [AesEcbEncrypt](https://github.com/duke-git/lancet/blob/v1/docs/cryptor_zh-CN.md#AesEcbEncrypt)
 -   [AesEcbDecrypt](https://github.com/duke-git/lancet/blob/v1/docs/cryptor_zh-CN.md#AesEcbDecrypt)
 -   [AesCbcEncrypt](https://github.com/duke-git/lancet/blob/v1/docs/cryptor_zh-CN.md#AesCbcEncrypt)
@@ -123,11 +126,12 @@ import "github.com/duke-git/lancet/cryptor"
 
 ### 3. datetime 日期时间处理包，格式化日期，比较日期。
 
-
 ```go
 import "github.com/duke-git/lancet/datetime"
 ```
+
 #### 函数列表:
+
 -   [AddDay](https://github.com/duke-git/lancet/blob/v1/docs/datetime_zh-CN.md#AddDay)
 -   [AddHour](https://github.com/duke-git/lancet/blob/v1/docs/datetime_zh-CN.md#AddHour)
 -   [AddMinute](https://github.com/duke-git/lancet/blob/v1/docs/datetime_zh-CN.md#AddMinute)
@@ -158,6 +162,7 @@ import "github.com/duke-git/lancet/datetime"
 -   [ToFormat](https://github.com/duke-git/lancet/blob/v1/docs/datetime_zh-CN.md#ToFormat)
 -   [ToFormatForTpl](https://github.com/duke-git/lancet/blob/v1/docs/datetime_zh-CN.md#ToFormatForTpl)
 -   [ToIso8601](https://github.com/duke-git/lancet/blob/v1/docs/datetime_zh-CN.md#ToIso8601)
+
 ### 4. fileutil 包支持文件基本操作。
 
 ```go
@@ -187,9 +192,10 @@ import "github.com/duke-git/lancet/fileutil"
 ```go
 import "github.com/duke-git/lancet/formatter"
 ```
-#### 函数列表:
-- [Comma](https://github.com/duke-git/lancet/blob/v1/docs/formatter_zh-CN.md#Comma)
 
+#### 函数列表:
+
+-   [Comma](https://github.com/duke-git/lancet/blob/v1/docs/formatter_zh-CN.md#Comma)
 
 ### function 函数包控制函数执行流程，包含部分函数式编程。
 
@@ -198,6 +204,7 @@ import "github.com/duke-git/lancet/function"
 ```
 
 #### 函数列表:
+
 -   [After](https://github.com/duke-git/lancet/blob/v1/docs/function_zh-CN.md#After)
 -   [Before](https://github.com/duke-git/lancet/blob/v1/docs/function_zh-CN.md#Before)
 -   [Curry](https://github.com/duke-git/lancet/blob/v1/docs/function_zh-CN.md#Curry)
@@ -213,6 +220,7 @@ import "github.com/duke-git/lancet/mathutil"
 ```
 
 #### Function list:
+
 -   [Exponent](https://github.com/duke-git/lancet/blob/v1/docs/mathutil_zh-CN.md#Exponent)
 -   [Fibonacci](https://github.com/duke-git/lancet/blob/v1/docs/mathutil_zh-CN.md#Fibonacci)
 -   [Factorial](https://github.com/duke-git/lancet/blob/v1/docs/mathutil_zh-CN.md#Factorial)
@@ -228,6 +236,7 @@ import "github.com/duke-git/lancet/netutil"
 ```
 
 #### 函数列表:
+
 -   [ConvertMapToQueryString](https://github.com/duke-git/lancet/blob/v1/docs/netutil_zh-CN.md#ConvertMapToQueryString)
 -   [EncodeUrl](https://github.com/duke-git/lancet/blob/v1/docs/netutil_zh-CN.md#EncodeUrl)
 -   [GetInternalIp](https://github.com/duke-git/lancet/blob/v1/docs/netutil_zh-CN.md#GetInternalIp)
@@ -251,10 +260,16 @@ import "github.com/duke-git/lancet/random"
 ```
 
 #### 函数列表:
+
 -   [RandBytes](https://github.com/duke-git/lancet/blob/v1/docs/random_zh-CN.md#RandBytes)
 -   [RandInt](https://github.com/duke-git/lancet/blob/v1/docs/random_zh-CN.md#RandInt)
 -   [RandString](https://github.com/duke-git/lancet/blob/v1/docs/random_zh-CN.md#RandString)
+-   [RandUpper](https://github.com/duke-git/lancet/blob/v1/docs/random_zh-CN.md#RandUpper)
+-   [RandLower](https://github.com/duke-git/lancet/blob/v1/docs/random_zh-CN.md#RandLower)
+-   [RandNumeral](https://github.com/duke-git/lancet/blob/v1/docs/random_zh-CN.md#RandNumeral)
+-   [RandNumeralOrLetter](https://github.com/duke-git/lancet/blob/v1/docs/random_zh-CN.md#RandNumeralOrLetter)
 -   [UUIdV4](https://github.com/duke-git/lancet/blob/v1/docs/random.md#UUIdV4)
+
 ### 9. retry 重试执行函数直到函数运行成功或被 context cancel。
 
 ```go
@@ -262,13 +277,13 @@ import "github.com/duke-git/lancet/retry"
 ```
 
 #### 函数列表:
+
 -   [Context](https://github.com/duke-git/lancet/blob/v1/docs/retry_zh-CN.md#Context)
 -   [Retry](https://github.com/duke-git/lancet/blob/v1/docs/retry_zh-CN.md#Retry)
 -   [RetryFunc](https://github.com/duke-git/lancet/blob/v1/docs/retry_zh-CN.md#RetryFunc)
 -   [RetryDuration](https://github.com/duke-git/lancet/blob/v1/docs/retry_zh-CN.md#RetryDuration)
 -   [RetryTimes](https://github.com/duke-git/lancet/blob/v1/docs/retry_zh-CN.md#RetryTimes)
 
-
 ### 10. slice 包包含操作切片的方法集合。
 
 ```go
@@ -276,6 +291,7 @@ import "github.com/duke-git/lancet/slice"
 ```
 
 #### 函数列表:
+
 -   [AppendIfAbsent](https://github.com/duke-git/lancet/blob/v1/docs/slice_zh-CN.md#AppendIfAbsent)
 -   [Contain](https://github.com/duke-git/lancet/blob/v1/docs/slice_zh-CN.md#Contain)
 -   [ContainSubSlice](https://github.com/duke-git/lancet/blob/v1/docs/slice_zh-CN.md#ContainSubSlice)
@@ -317,7 +333,6 @@ import "github.com/duke-git/lancet/slice"
 -   [UpdateByIndex](https://github.com/duke-git/lancet/blob/v1/docs/slice_zh-CN.md#UpdateByIndex)
 -   [Without](https://github.com/duke-git/lancet/blob/v1/docs/slice_zh-CN.md#Without)
 
-
 ### 12. strutil 包含处理字符串的相关函数。
 
 ```go
@@ -344,7 +359,6 @@ import "github.com/duke-git/lancet/strutil"
 -   [Wrap](https://github.com/duke-git/lancet/blob/v1/docs/strutil_zh-CN.md#Wrap)
 -   [Unwrap](https://github.com/duke-git/lancet/blob/v1/docs/strutil_zh-CN.md#Unwrap)
 
-
 ### 13. system 包含 os, runtime, shell command 相关函数。
 
 ```go
@@ -352,6 +366,7 @@ import "github.com/duke-git/lancet/system"
 ```
 
 #### 函数列表:
+
 -   [IsWindows](https://github.com/duke-git/lancet/blob/v1/docs/system_zh-CN.md#IsWindows)
 -   [IsLinux](https://github.com/duke-git/lancet/blob/v1/docs/system_zh-CN.md#IsLinux)
 -   [IsMac](https://github.com/duke-git/lancet/blob/v1/docs/system_zh-CN.md#IsMac)
@@ -367,6 +382,7 @@ import "github.com/duke-git/lancet/system"
 ```go
 import "github.com/duke-git/lancet/validator"
 ```
+
 #### 函数列表:
 
 -   [ContainChinese](https://github.com/duke-git/lancet/blob/v1/docs/validator_zh-CN.md#ContainChinese)
@@ -397,7 +413,6 @@ import "github.com/duke-git/lancet/validator"
 -   [IsWeakPassword](https://github.com/duke-git/lancet/blob/v1/docs/validator_zh-CN.md#IsWeakPassword)
 -   [IsZeroValue](https://github.com/duke-git/lancet/blob/v1/docs/validator_zh-CN.md#IsZeroValue)
 
-
 ## 如何贡献代码
 
 非常感激任何的代码提交以使 lancet 的功能越来越强大。创建 pull request 时请遵守以下规则。

docs/random.md

@@ -1,4 +1,5 @@
 # Random
+
 Package random implements some basic functions to generate random int and string.
 
 <div STYLE="page-break-after: always;"></div>
@@ -7,10 +8,10 @@ Package random implements some basic functions to generate random int and string
 
 [https://github.com/duke-git/lancet/blob/v1/random/random.go](https://github.com/duke-git/lancet/blob/v1/random/random.go)
 
-
 <div STYLE="page-break-after: always;"></div>
 
 ## Usage:
+
 ```go
 import (
     "github.com/duke-git/lancet/random"
@@ -20,17 +21,23 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## Index
+
 -   [RandBytes](#RandBytes)
 -   [RandInt](#RandInt)
 -   [RandString](#RandString)
+-   [RandUpper](#RandUpper)
+
+-   [RandLower](#RandLower)
+-   [RandNumeral](#RandNumeral)
+-   [RandNumeralOrLetter](#RandNumeralOrLetter)
 -   [UUIdV4](#UUIdV4)
 
 <div STYLE="page-break-after: always;"></div>
 
 ## Documentation
 
-
 ### <span id="RandBytes">RandBytes</span>
+
 <p>Generate random byte slice.</p>
 
 <b>Signature:</b>
@@ -38,6 +45,7 @@ import (
 ```go
 func RandBytes(length int) []byte
 ```
+
 <b>Example:</b>
 
 ```go
@@ -54,8 +62,8 @@ func main() {
 }
 ```
 
-
 ### <span id="RandInt">RandInt</span>
+
 <p>Generate random int between min and max, may contain min, not max.</p>
 
 <b>Signature:</b>
@@ -63,6 +71,7 @@ func main() {
 ```go
 func RandInt(min, max int) int
 ```
+
 <b>Example:</b>
 
 ```go
@@ -79,16 +88,16 @@ func main() {
 }
 ```
 
+### <span id="RandString">RandString</span>
 
-
+<p>Generate random given length string. only contains letter (a-zA-Z)</p>
-### <span id="RandString">RandInt</span>
-<p>Generate random given length string.</p>
 
 <b>Signature:</b>
 
 ```go
 func RandString(length int) string
 ```
+
 <b>Example:</b>
 
 ```go
@@ -101,14 +110,116 @@ import (
 
 func main() {
 	randStr := random.RandString(6)
-	fmt.Println(randStr)
+	fmt.Println(randStr) //pGWsze
 }
 ```
 
+### <span id="RandUpper">RandUpper</span>
 
+<p>Generate a random upper case string</p>
 
+<b>Signature:</b>
+
+```go
+func RandUpper(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandString(6)
+	fmt.Println(randStr) //PACWGF
+}
+```
+
+### <span id="RandLower">RandLower</span>
+
+<p>Generate a random lower case string</p>
+
+<b>Signature:</b>
+
+```go
+func RandLower(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandLower(6)
+	fmt.Println(randStr) //siqbew
+}
+```
+
+### <span id="RandNumeral">RandNumeral</span>
+
+<p>Generate a random numeral string</p>
+
+<b>Signature:</b>
+
+```go
+func RandNumeral(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandNumeral(6)
+	fmt.Println(randStr) //035172
+}
+```
+
+### <span id="RandNumeralOrLetter">RandNumeralOrLetter</span>
+
+<p>generate a random numeral or letter string</p>
+
+<b>Signature:</b>
+
+```go
+func RandNumeralOrLetter(length int) string
+```
+
+<b>Example:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandNumeralOrLetter(6)
+	fmt.Println(randStr) //0aW7cQ
+}
+```
 
 ### <span id="UUIdV4">UUIdV4</span>
+
 <p>Generate a random UUID of version 4 according to RFC 4122.</p>
 
 <b>Signature:</b>
@@ -116,6 +227,7 @@ func main() {
 ```go
 func UUIdV4() (string, error)
 ```
+
 <b>Example:</b>
 
 ```go
@@ -134,5 +246,3 @@ func main() {
 	fmt.Println(uuid)
 }
 ```
-
-

docs/random_zh-CN.md

@@ -1,4 +1,5 @@
 # Random
+
 random 随机数生成器包，可以生成随机[]bytes, int, string。
 
 <div STYLE="page-break-after: always;"></div>
@@ -7,10 +8,10 @@ random随机数生成器包，可以生成随机[]bytes, int, string。
 
 [https://github.com/duke-git/lancet/blob/v1/random/random.go](https://github.com/duke-git/lancet/blob/v1/random/random.go)
 
-
 <div STYLE="page-break-after: always;"></div>
 
 ## 用法:
+
 ```go
 import (
     "github.com/duke-git/lancet/random"
@@ -20,18 +21,23 @@ import (
 <div STYLE="page-break-after: always;"></div>
 
 ## 目录
+
 -   [RandBytes](#RandBytes)
 -   [RandInt](#RandInt)
 -   [RandString](#RandString)
-- [UUIdV4](#UUIdV4)
+-   [RandUpper](#RandUpper)
 
+-   [RandLower](#RandLower)
+-   [RandNumeral](#RandNumeral)
+-   [RandNumeralOrLetter](#RandNumeralOrLetter)
+-   [UUIdV4](#UUIdV4)
 
 <div STYLE="page-break-after: always;"></div>
 
 ## 文档
 
-
 ### <span id="RandBytes">RandBytes</span>
+
 <p>生成随机字节切片</p>
 
 <b>函数签名:</b>
@@ -39,6 +45,7 @@ import (
 ```go
 func RandBytes(length int) []byte
 ```
+
 <b>例子:</b>
 
 ```go
@@ -55,8 +62,8 @@ func main() {
 }
 ```
 
-
 ### <span id="RandInt">RandInt</span>
+
 <p>生成随机int, 范围[min, max)</p>
 
 <b>函数签名:</b>
@@ -64,6 +71,7 @@ func main() {
 ```go
 func RandInt(min, max int) int
 ```
+
 <b>例子:</b>
 
 ```go
@@ -80,16 +88,16 @@ func main() {
 }
 ```
 
+### <span id="RandString">RandString</span>
 
-
+<p>生成给定长度的随机字符串，只包含字母(a-zA-Z)</p>
-### <span id="RandString">RandInt</span>
-<p>生成随机给定长度的随机字符串</p>
 
 <b>函数签名:</b>
 
 ```go
 func RandString(length int) string
 ```
+
 <b>例子:</b>
 
 ```go
@@ -102,13 +110,116 @@ import (
 
 func main() {
 	randStr := random.RandString(6)
-	fmt.Println(randStr)
+	fmt.Println(randStr) //pGWsze
 }
 ```
 
+### <span id="RandUpper">RandUpper</span>
 
+<p>生成给定长度的随机大写字母字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func RandUpper(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandString(6)
+	fmt.Println(randStr) //PACWGF
+}
+```
+
+### <span id="RandLower">RandLower</span>
+
+<p>生成给定长度的随机小写字母字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func RandLower(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandLower(6)
+	fmt.Println(randStr) //siqbew
+}
+```
+
+### <span id="RandNumeral">RandNumeral</span>
+
+<p>生成给定长度的随机数字字符串</p>
+
+<b>函数签名:</b>
+
+```go
+func RandNumeral(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandNumeral(6)
+	fmt.Println(randStr) //035172
+}
+```
+
+### <span id="RandNumeralOrLetter">RandNumeralOrLetter</span>
+
+<p>生成给定长度的随机字符串（数字+字母)</p>
+
+<b>函数签名:</b>
+
+```go
+func RandNumeralOrLetter(length int) string
+```
+
+<b>例子:</b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/random"
+)
+
+func main() {
+	randStr := random.RandNumeralOrLetter(6)
+	fmt.Println(randStr) //0aW7cQ
+}
+```
 
 ### <span id="UUIdV4">UUIdV4</span>
+
 <p>生成UUID v4字符串</p>
 
 <b>函数签名:</b>
@@ -116,6 +227,7 @@ func main() {
 ```go
 func UUIdV4() (string, error)
 ```
+
 <b>例子:</b>
 
 ```go
@@ -134,5 +246,3 @@ func main() {
 	fmt.Println(uuid)
 }
 ```
-
-

random/random.go

@@ -12,18 +12,12 @@ import (
 	"time"
 )
 
-// RandString generate random string
+const (
-// see https://stackoverflow.com/questions/22892120/how-to-generate-a-random-string-of-a-fixed-length-in-go
+	NUMERAL       = "0123456789"
-func RandString(length int) string {
+	LOWER_LETTERS = "abcdefghijklmnopqrstuvwxyz"
-	const letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	UPPER_LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-
+	LETTERS       = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
-	b := make([]byte, length)
+)
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
-	for i := range b {
-		b[i] = letters[r.Int63()%int64(len(letters))]
-	}
-	return string(b)
-}
 
 // RandInt generate random int between min and max, maybe min,  not be max
 func RandInt(min, max int) int {
@@ -50,6 +44,41 @@ func RandBytes(length int) []byte {
 	return b
 }
 
+// RandString generate random string
+func RandString(length int) string {
+	return random(LETTERS, length)
+}
+
+// RandUpper generate a random upper case string
+func RandUpper(length int) string {
+	return random(UPPER_LETTERS, length)
+}
+
+// RandLower generate a random lower case string
+func RandLower(length int) string {
+	return random(LOWER_LETTERS, length)
+}
+
+// RandNumeral generate a random numeral string
+func RandNumeral(length int) string {
+	return random(NUMERAL, length)
+}
+
+// RandNumeralOrLetter generate a random numeral or letter string
+func RandNumeralOrLetter(length int) string {
+	return random(NUMERAL+LETTERS, length)
+}
+
+// random generate a random string based on given string range
+func random(s string, length int) string {
+	b := make([]byte, length)
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	for i := range b {
+		b[i] = s[r.Int63()%int64(len(s))]
+	}
+	return string(b)
+}
+
 // UUIdV4 generate a random UUID of version 4 according to RFC 4122
 func UUIdV4() (string, error) {
 	uuid := make([]byte, 16)

random/random_test.go

@@ -19,6 +19,51 @@ func TestRandString(t *testing.T) {
 	assert.Equal(true, reg.MatchString(randStr))
 }
 
+func TestRandUpper(t *testing.T) {
+	pattern := `^[A-Z]+$`
+	reg := regexp.MustCompile(pattern)
+
+	randStr := RandUpper(6)
+
+	assert := internal.NewAssert(t, "TestRandUpper")
+	assert.Equal(6, len(randStr))
+	assert.Equal(true, reg.MatchString(randStr))
+}
+
+func TestRandLower(t *testing.T) {
+	pattern := `^[a-z]+$`
+	reg := regexp.MustCompile(pattern)
+
+	randStr := RandLower(6)
+
+	assert := internal.NewAssert(t, "TestRandLower")
+	assert.Equal(6, len(randStr))
+	assert.Equal(true, reg.MatchString(randStr))
+}
+
+func TestRandNumeral(t *testing.T) {
+	pattern := `^[0-9]+$`
+	reg := regexp.MustCompile(pattern)
+
+	randStr := RandNumeral(12)
+
+	assert := internal.NewAssert(t, "TestRandNumeral")
+	assert.Equal(12, len(randStr))
+	assert.Equal(true, reg.MatchString(randStr))
+}
+
+func TestRandNumeralOrLetter(t *testing.T) {
+	pattern := `^[0-9a-zA-Z]+$`
+	reg := regexp.MustCompile(pattern)
+
+	randStr := RandNumeralOrLetter(10)
+	t.Log(randStr)
+
+	assert := internal.NewAssert(t, "TestRandNumeralOrLetter")
+	assert.Equal(10, len(randStr))
+	assert.Equal(true, reg.MatchString(randStr))
+}
+
 func TestRandInt(t *testing.T) {
 	assert := internal.NewAssert(t, "TestRandInt")