For Loop

透過loop可以幫你解決重複性的工作。robot提供兩種Format: For In Element and For In Range

For In Element

For In Element即loop目標以element為主，語法為:For | ${target} | in | @{target_list}。

Example1: Traverse a single element with a list variable 

@{elements} | Set Variable | John        | Mary
:For        | ${element}   | in          | @{elements}
            | log          | ${element}

Example2: Traverse a piar of elements with a list variable 

@{elements} | Set Variable | John        | 39         | Mary        | 20
:For        | ${name}      | ${age}      | in         | @{elements}
            | log          | ${name},${age}

RobotFramework無法處理太複雜的資料結構，list是最常使用的儲存方式。可以透過Example2的方式去取各別有意義的資料。

For In Range

For In Element即loop目標以range為主，語法為:For | ${index} | in range | ${range}。

Example1: From 0 to n 

comment     | dump 0, 1, ..., 9
${n}        | Set Variable | 10
:For        | ${i}         | in range     | ${n}
            | log          | ${i}

Example2: From n1 to n2 

comment     | dump 1, 2, ..., 10
${n1}       | Set Variable | 1
${n2}       | Set Variable | 11
:For        | ${i}         | in range     | ${n1}      | ${n2}
            | log          | ${i}

Example3: From n1 to n2 and increases by k 

comment     | dump 1, 3, 5, ..., 9
${n1}       | Set Variable | 1
${n2}       | Set Variable | 11
${k}        | Set Variable | 2
:For        | ${i}         | in range     | ${n1}      | ${n2}     | ${k}
            | log          | ${i}

Practice

Sum of n1 to n2 and increases by k

修改For In Range的example3即可完成這次練習。 

${n1}       | Set Variable | 1
${n2}       | Set Variable | 11
${k}        | Set Variable | 2
${sum}      | Set Variable | 0
:For        | ${i}         | in range     | ${n1}                 | ${n2}     | ${k}
            | ${sum}       | Evaluate     | int(${sun})+int(${i}) 
log         | ${sum}
可以發現log keyword沒放在:For的縮排中，代表log不在for loop的scope內，不需要重複執行。

9X9 Multiplication Table

RobotFramework無法做nested for loop，因此我們必須將內部迴圈實做成Keyword: Dump Multiplication Table。
第一個for loop從2到9，並傳到Dump Multiplication Table中計算各個結果。 

:For | ${i}                      | In Range                | 2                       | 10
     | Dump Multiplication Table | ${i}
Dump Multiplication Table接收的傳入值，將其各別乘以1~9。 
# Keyword Name: Dump Multiplication Table
# Arguments:    ${index}
:For | ${i}     | In Range                | 1                       | 10
     | ${result}| Evaluate                | int(${index})*int(${i})
     | log      | ${index}*{i} = ${result}

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Reference