Question

如何在AWS Lambda中执行return语句之前等待forEach循环完成？

# @param A : list of list of integers
# @return the same list modified
def rotate(A):
    for row in range(len(A) // 2):
        for col in range(row, len(A)-1 - row): # First col already takes care of last.
            r = row
            c = col
            tmp1 = A[r][c]
            while True:
                next_r = c
                next_c = len(A) - 1 - r
                tmp2 = A[next_r][next_c]
                A[next_r][next_c] = tmp1
                if next_r == row and next_c == col:
                    break
                tmp1 = tmp2
                r = next_r
                c = next_c
    return A

Answer 1

您已经在使用异步，因此请使用map返回承诺列表，并通过Promise.all()等待所有承诺：

module.exports.shipments = async (event) => {
    const axios = require("axios");
    let data = JSON.parse(event.body);
    let url = data.apiURL + "/api/1.1/wf/bulkshipments/initialize";
    let patchURL = data.apiURL + "/api/1.1/obj/company/" + data.companyID;

    let promises = data.shipments.map(item =>
        axios.post(url, {
            batchID: data.batchID,
            companyID: data.companyID,
            shipment: item})
        })
    );

    await Promise.all(promises);

    return {
      statusCode: 200,
      body: JSON.stringify({
        message: 'Created successfully!',
        totalShipments: data.shipments.length,
      }, null, 2),
    };
};

要等待每个呼叫，而不是同时触发所有发帖请求，请使用for...of loop：

module.exports.shipments = async (event) => {
    const axios = require("axios");
    let data = JSON.parse(event.body);
    let url = data.apiURL + "/api/1.1/wf/bulkshipments/initialize";
    let patchURL = data.apiURL + "/api/1.1/obj/company/" + data.companyID;

    for (let item of data.shipments) {
        await axios.post(url, {
            batchID: data.batchID,
            companyID: data.companyID,
            shipment: item})
        });
    }

    await Promise.all(promises);

    return {
      statusCode: 200,
      body: JSON.stringify({
        message: 'Created successfully!',
        totalShipments: data.shipments.length,
      }, null, 2),
    };
};

在AWS Lambda函数中等待forEach循环

1 个答案: