Automation One By One - Robot Framework - 变量及赋值

前面已经提到变量有三类，一类是scalar variable ${variable},一类是list variable,还有一类是内置(Built-in)的变量.

1. 给scalar variable类型的变量赋值：${scalar variable}

（1）${scalar variable}=  simple strings
（2）${scalar variable}=  objects
    无论scalar类型的变量被赋予什么值，这个值先被转换成Unicode，然后再按字符串显示出来。转换的过程相当于调用这个对象的__unicode__，__str__

2. 给list variable赋值: @{variable}

（1）列表变量中的值，可以是一个，也可以是多数（无数），还可以是空
（2）列表变量的值通常是字符类型的，其它类型的也可以
（3）可以通过@{NAME}[i]形式来访问列表中的某一个值
（4）可将list variables当作scalar类型的变量使用，使用方法是将list变量的符号从@替换成$就可以了；这种表达式让我们使用built-in类库及Collection类库中list相关的keywords成为可能。
（5）list变量可以应用在setting table中，但仅限于一部分的settings命令可用。

• 对于Library及Resource的settings来说list变量不能作为其name使用，只能作为argument使用
• 对于Setup/Teardown的settings来说list变量不能当作keyword的name使用，只能作为argument使用
• 对于tag的settings来说可以随意使用
• 对于不支持list变量的settings来说，我们可以使用scalar变量的形式来表达（如library及setup中的name不能使用list变量，我们可以用scalar变量代替list变量）

Using list variables with settings

Settings	Value	Value	Comment
Library	ExampleLibrary	@{LIB ARGS}	# This works
Library	${LIBRARY}	@{LIB ARGS}	# This works
Library	@{NAME AND ARGS}		# This does not work
Suite Setup	Some Keyword	@{KW ARGS}	# This works
Suite Setup	${KEYWORD}	@{KW ARGS}	# This works
Suite Setup	@{KEYWORD}		# This does not work
Default Tags	@{TAGS}		# This works

3. 给Envrionment Variables赋值：%{ENV_VAR_NAME}
（1）只能赋值string类型的值
（2）可于OperatingSystem library类库中的keyword一块应用


4. 可以将keyword中返回的值作为变量存储

${keyword_return_value}=  Get Matching Xpath Count  [locator]
${keyword_return_value}=  Get Element Attribute  [locator]
...
5. 内置Build-in变量

Available operating-system-related built-in variables

Variable	Explanation
${CURDIR}	An absolute path to the directory where the test data file is located. This variable is case-sensitive.
${TEMPDIR}	An absolute path to the system temporary directory. In UNIX-like systems this is typically/tmp, and in Windowsc:\Documents and Settings\<user>\Local Settings\Temp.
${EXECDIR}	An absolute path to the directory where test execution was started from. New in Robot Framework 2.1.
${/}	The system directory path separator./in UNIX-like systems,\in Windows.
${:}	The system path element separator.:in UNIX-like systems and;in Windows.

Variable	Explanation	Available
${TEST NAME}	The name of the current test case.	Test case
@{TEST TAGS}	Contains the tags of the current test case in alphabetical order.	Test case
${TEST STATUS}	The status of the current test case, either PASS or FAIL.	Test teardown
${TEST MESSAGE}	The possible error message of the current test case.	Test teardown
${PREV TEST NAME}	The name of the previous test case, or an empty string if no tests have been executed yet.	Everywhere
${PREV TEST STATUS}	The status of the previous test case: either PASS, FAIL or an empty string when no tests have been executed.	Everywhere
${PREV TEST MESSAGE}	The possible error message of the previous test case.	Everywhere
${SUITE NAME}	The full name of the current test suite.	Everywhere
${SUITE SOURCE}	An absolute path to the suite file or directory. New in Robot Framework 2.5.	Everywhere
${SUITE STATUS}	The status of the current test case, either PASS or FAIL.	Suite teardown
${SUITE MESSAGE}	The full message of the current test suite, including statistics.	Suite teardown
${OUTPUT FILE}	An absolute path to the currentoutput file. Has different values during execution whenoutputs are split.	Everywhere
${LOG FILE}	An absolute path to the currentlog fileor string NONE when no log file is created. Has different values during execution whenoutputs are split.	Everywhere
${REPORT FILE}	An absolute path to thereport fileor string NONE when no report is created.	Everywhere
${SUMMARY FILE}	An absolute path to thesummary fileor string NONE when no summary is created.	Everywhere
${DEBUG FILE}	An absolute path to thedebug fileor string NONE when no debug file is created.	Everywhere
${OUTPUT DIR}	An absolute path to theoutput directory.	Everywhere