RF标准库String的使用

问题：

用robotframework-ride编写金额断言时，获取的金额数据存在千分位分隔符“，”，但是对比数据不存在“，”，而且带千分位分隔符的金额（实际上是字符串）无法转化为数字进行比较。

解决方案：

想办法将带有千分位分隔符的金额中的“，”去掉，这样我们就获得了一个完整的系统可识别的数字。通过关键字should be equal as numbers 就可以成功验证通过了。通过查阅资料，可以利用robotframework的标准库String来实现需求。话不多说，放上标准库的官方文档http://robotframework.org/robotframework/latest/libraries/String.html

步骤用法：

1、robotframework内置String标准库，无需做其他安装操作，在测试套集中直接引入即可。鼠标点击选择一个测试套集（testsuite），右侧Add Import 点击Library，弹窗在Name输入框中输入String，点击确定。导入String标准库，如果列表展示为黑色表示导入成功，如果为红色表示导入失败，需要检查你输入是否正确，或者检查robotframework是否为最新版。一般都可以成功引入的。

2、我主要使用的是Remove String关键字，这里也主要就他的使用方法做详细描述。

格式：${存放截取后字符串的变量} Remove String ${存放截取前的字符串的变量} 想要去掉的字符

（如果想要去掉多个连续字符，填写在一个格里即可；如果想要去掉多个不连续的字符，则需要填到另一个格里）

3、操作结束后，可以用log打印出变量的值，可以看到想要的结果，由此解决了困扰我半天的问题。

截取String库官方文档内容

Introduction

A test library for string manipulation and verification.String is Robot Framework's standard library for manipulating strings

Following keywords from BuiltIn library can also be used with strings:

Catenate
Get Length
Length Should Be
Should (Not) Be Empty
Should (Not) Be Equal (As Strings/Integers/Numbers)
Should (Not) Match (Regexp)
Should (Not) Contain
Should (Not) Start With
Should (Not) End With
Convert To String
Convert To Bytes

Altogether 30 keywords.

Keyword Arguments Documentation

Convert To Lowercase

string

Converts string to lowercase.

Examples:

${str1} =	Convert To Lowercase	ABC
${str2} =	Convert To Lowercase	1A2c3D
Should Be Equal	${str1}	abc
Should Be Equal	${str2}	1a2c3d

New in Robot Framework 2.8.6.

Convert To Uppercase

string

Converts string to uppercase.

Examples:

${str1} =	Convert To Uppercase	abc
${str2} =	Convert To Uppercase	1a2C3d
Should Be Equal	${str1}	ABC
Should Be Equal	${str2}	1A2C3D

New in Robot Framework 2.8.6.

Decode Bytes To String

bytes, encoding,errors=strict

Decodes the given bytes to a Unicode string using the given encoding.

errors argument controls what to do if decoding some bytes fails. All values accepted by decode method in Python are valid, but in practice the following values are most useful:

strict: fail if characters cannot be decoded (default)
ignore: ignore characters that cannot be decoded
replace: replace characters that cannot be decoded with a replacement character

Examples:

${string} =	Decode Bytes To String	${bytes}	UTF-8
${string} =	Decode Bytes To String	${bytes}	ASCII	errors=ignore

Use Encode String To Bytes if you need to convert Unicode strings to byte strings, and Convert To String in BuiltIn if you need to convert arbitrary objects to Unicode strings.

Encode String To Bytes

string, encoding,errors=strict

Encodes the given Unicode string to bytes using the given encoding.

errors argument controls what to do if encoding some characters fails. All values accepted by encode method in Python are valid, but in practice the following values are most useful:

strict: fail if characters cannot be encoded (default)
ignore: ignore characters that cannot be encoded
replace: replace characters that cannot be encoded with a replacement character

Examples:

${bytes} =	Encode String To Bytes	${string}	UTF-8
${bytes} =	Encode String To Bytes	${string}	ASCII	errors=ignore

Use Convert To Bytes in BuiltIn if you want to create bytes based on character or integer sequences. Use Decode Bytes To String if you need to convert byte strings to Unicode strings and Convert To String in BuiltIn if you need to convert arbitrary objects to Unicode.

Fetch From Left

string, marker

Returns contents of the string before the first occurrence of marker.

If the marker is not found, whole string is returned.

Fetch From Right

string, marker

Returns contents of the string after the last occurrence of marker.

If the marker is not found, whole string is returned.

Generate Random String

length=8, chars=[LETTERS][NUMBERS]

Generates（生成） a string with a desired（期望） length from the given chars.

The population sequence chars contains the characters to use when generating the random string. It can contain any characters, and it is possible to use special markers explained in the table below:

Marker	Explanation
`[LOWER]`	Lowercase ASCII characters from `a` to `z`.
`[UPPER]`	Uppercase ASCII characters from `A` to `Z`.
`[LETTERS]`	Lowercase and uppercase ASCII characters.
`[NUMBERS]`	Numbers from 0 to 9.

Examples:

log:

20170719 11:20:59.200 : INFO : ${ret} = bjgo5Rz7
20170719 11:20:59.200 : INFO : ${low} = ourdecxrjuej
20170719 11:20:59.200 : INFO : ${up} = ULZYTGLIEISI
20170719 11:20:59.200 : INFO : ${LETT} = HUuBavRQsTKx
20170719 11:20:59.200 : INFO : ${NUM} = 823509837958
20170719 11:20:59.200 : INFO : ${bin} = 01010001
20170719 11:20:59.200 : INFO : ${hex} = 2154

Get Line

string, line_number

Returns the specified line from the given string.

Line numbering starts from 0 and it is possible to use negative indices(负数) to refer to lines from the end. The line is returned without the newline character.

Examples:

${first} =	Get Line	${string}	0
${2nd last} =	Get Line	${string}	-2

Use Split To Lines if all lines are needed.

Get Line Count

string

Returns and logs the number of lines in the given string.

Get Lines Containing String

string, pattern,case_insensitive=False

Returns lines of the given string that contain the pattern.

The pattern is always considered to be a normal string, not a glob or regexp pattern. A line matches if the pattern is found anywhere on it.

The match is case-sensitive by default, but giving case_insensitive a true value makes it case-insensitive. The value is considered true if it is a non-empty string that is not equal to false or no. If the value is not a string, its truth value is got directly in Python.

Lines are returned as one string catenated back together with newlines. Possible trailing newline is never returned. The number of matching lines is automatically logged.

Examples:

${lines} =	Get Lines Containing String	${result}	An example
${ret} =	Get Lines Containing String	${ret}	FAIL	case-insensitive

See Get Lines Matching Pattern and Get Lines Matching Regexp if you need more complex pattern matching.

Get Lines Matching Pattern

string, pattern,case_insensitive=False

Returns lines of the given string that match the pattern.

The pattern is a glob pattern where:

`*`	matches everything
`?`	matches any single character
`[chars]`	matches any character inside square brackets (e.g. `[abc]` matches either `a`, `b` or `c`)
`[!chars]`	matches any character not inside square brackets

A line matches only if it matches the pattern fully.

Lines are returned as one string catenated back together with newlines. Possible trailing newline is never returned. The number of matching lines is automatically logged.

Examples:

${lines} =	Get Lines Matching Pattern	${result}	Wild???? example
${ret} =	Get Lines Matching Pattern	${ret}	FAIL: *	case_insensitive=true

See Get Lines Matching Regexp if you need more complex patterns and Get Lines Containing String if searching literal strings is enough.

Get Lines Matching Regexp

string, pattern,partial_match=False

Returns lines of the given string that match the regexp pattern.

See BuiltIn.Should Match Regexp for more information about Python regular expression syntax in general and how to use it in Robot Framework test data in particular.

By default lines match only if they match the pattern fully, but partial matching can be enabled by giving the partial_match argument a true value. The value is considered true if it is a non-empty string that is not equal to false or no. If the value is not a string, its truth value is got directly in Python.

If the pattern is empty, it matches only empty lines by default. When partial matching is enabled, empty pattern matches all lines.

Notice that to make the match case-insensitive, you need to prefix the pattern with case-insensitive flag (?i).

Lines are returned as one string concatenated back together with newlines. Possible trailing newline is never returned. The number of matching lines is automatically logged.

Examples:

${lines} =	Get Lines Matching Regexp	${result}	Reg\\w{3} example
${lines} =	Get Lines Matching Regexp	${result}	Reg\\w{3} example	partial_match=true
${ret} =	Get Lines Matching Regexp	${ret}	(?i)FAIL: .*

See Get Lines Matching Pattern and Get Lines Containing String if you do not need full regular expression powers (and complexity).

partial_match argument is new in Robot Framework 2.9. In earlier versions exact match was always required.

Get Regexp Matches

string, pattern,*groups

Returns a list of all non-overlapping matches in the given string.

string is the string to find matches from and pattern is the regular expression. See BuiltIn.Should Match Regexp for more information about Python regular expression syntax in general and how to use it in Robot Framework test data in particular.

If no groups are used, the returned list contains full matches. If one group is used, the list contains only contents of that group. If multiple groups are used, the list contains tuples that contain individual group contents. All groups can be given as indexes (starting from 1) and named groups also as names.

Examples:

${no match} =	Get Regexp Matches	the string	xxx
${matches} =	Get Regexp Matches	the string	t..
${one group} =	Get Regexp Matches	the string	t(..)	1
${named group} =	Get Regexp Matches	the string	t(?P<name>..)	name
${two groups} =	Get Regexp Matches	the string	t(.)(.)	1	2

${no match} = []
${matches} = ['the', 'tri']
${one group} = ['he', 'ri']
${named group} = ['he', 'ri']
${two groups} = [('h', 'e'), ('r', 'i')]

New in Robot Framework 2.9.

Get Substring

string, start,end=None

Returns a substring from start index to end index.可截取到想要的自字符串

The start index is inclusive and end is exclusive. Indexing starts from 0, and it is possible to use negative indices to refer to characters from the end.

Examples:

${ignore first} =	Get Substring	${string}	1
${ignore last} =	Get Substring	${string}		-1
${5th to 10th} =	Get Substring	${string}	4	10
${first two} =	Get Substring	${string}		1
${last two} =	Get Substring	${string}	-2

Remove String

string, *removables

Removes all removables from the given string.移除掉字符串中给定的字符

removables are used as literal strings. Each removable will be matched to a temporary string from which preceding removables have been already removed. See second example below.

Use Remove String Using Regexp if more powerful pattern matching is needed. If only a certain number of matches should be removed, Replace String or Replace String Using Regexp can be used.

A modified version of the string is returned and the original string is not altered.

Examples:

${str} =	Remove String	Robot Framework	work
Should Be Equal	${str}	Robot Frame
${str} =	Remove String	Robot Framework	o	bt
Should Be Equal	${str}	R Framewrk

New in Robot Framework 2.8.2.

Remove String Using Regexp

string, *patterns

Removes patterns from the given string.

This keyword is otherwise identical to Remove String, but the patterns to search for are considered to be a regular expression. See Replace String Using Regexp for more information about the regular expression syntax. That keyword can also be used if there is a need to remove only a certain number of occurrences.

New in Robot Framework 2.8.2.

Replace String

string, search_for,replace_with,count=-1

Replaces search_for in the given string with replace_with.

search_for is used as a literal string. See Replace String Using Regexp if more powerful pattern matching is needed. If you need to just remove a string see Remove String.

If the optional argument count is given, only that many occurrences from left are replaced. Negative count means that all occurrences are replaced (default behaviour) and zero means that nothing is done.

A modified version of the string is returned and the original string is not altered.

Examples:

${str} =	Replace String	Hello, world!	world	tellus
Should Be Equal	${str}	Hello, tellus!
${str} =	Replace String	Hello, world!	l	${EMPTY}	count=1
Should Be Equal	${str}	Helo, world!

Replace String Using Regexp

string, pattern,replace_with,count=-1

Replaces pattern in the given string with replace_with.

This keyword is otherwise identical to Replace String, but the pattern to search for is considered to be a regular expression. See BuiltIn.Should Match Regexp for more information about Python regular expression syntax in general and how to use it in Robot Framework test data in particular.

If you need to just remove a string see Remove String Using Regexp.

Examples:

${str} =	Replace String Using Regexp	${str}	20\\d\\d-\\d\\d-\\d\\d	<DATE>
${str} =	Replace String Using Regexp	${str}	(Hello\|Hi)	${EMPTY}	count=1

Should Be Byte String

item, msg=None

Fails if the given item is not a byte string.

Use Should Be Unicode String if you want to verify the item is a Unicode string, or Should Be String if both Unicode and byte strings are fine. See Should Be String for more details about Unicode strings and byte strings.