公告:所有在
2025 年 4 月 15 日之前注册使用 Earth Engine 的非商业项目都必须
验证是否符合非商业性质的资格条件,才能继续使用 Earth Engine。
ee.List.get
使用集合让一切井井有条
根据您的偏好保存内容并对其进行分类。
返回列表中指定位置的元素。负索引从列表末尾反向计数。
示例
代码编辑器 (JavaScript)
// An ee.List object.
var list = ee.List([5, 10, 15, 20, 25, 30]);
// Fetch elements at specified 0-based positions in the list.
print('The second element', list.get(1));
print('The fourth element', list.get(3));
print('The last element', list.get(-1));
print('The second to last element', list.get(-2));
// ee.Number and integer computed objects are valid inputs.
print('Computed object index input', list.get(list.get(0)));
// The result of ee.List.get is an ambiguous object type. You need to cast the
// result to the expected type to use it in subsequent instance methods. For
// example, if you are fetching a number and wish to add it to another number,
// you must cast the .get() result as an ee.Number.
print('Add fetched number to another number', ee.Number(list.get(1)).add(2));
Python 设置
如需了解 Python API 和如何使用 geemap
进行交互式开发,请参阅
Python 环境页面。
import ee
import geemap.core as geemap
Colab (Python)
# An ee.List object.
ee_list = ee.List([5, 10, 15, 20, 25, 30])
# Fetch elements at specified 0-based positions in the list.
print('The second element:', ee_list.get(1).getInfo())
print('The fourth element:', ee_list.get(3).getInfo())
print('The last element:', ee_list.get(-1).getInfo())
print('The second to last element:', ee_list.get(-2).getInfo())
# ee.Number and integer computed objects are valid inputs.
print('Computed object index input:', ee_list.get(list.get(0)).getInfo())
# The result of ee.List.get is an ambiguous object type. You need to cast the
# result to the expected type to use it in subsequent instance methods. For
# example, if you are fetching a number and wish to add it to another number,
# you must cast the .get() result as an ee.Number.
print('Add fetched number to another number:',
ee.Number(list.get(1)).add(2).getInfo())
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最后更新时间 (UTC):2025-07-26。
[null,null,["最后更新时间 (UTC):2025-07-26。"],[[["\u003cp\u003e\u003ccode\u003eList.get()\u003c/code\u003e retrieves an element from an Earth Engine List object at a specified index.\u003c/p\u003e\n"],["\u003cp\u003eNegative index values can be used to access elements from the end of the list, with -1 representing the last element.\u003c/p\u003e\n"],["\u003cp\u003eThe returned element's type is ambiguous and might require explicit casting to a specific Earth Engine type for further operations (e.g., converting to ee.Number to perform calculations).\u003c/p\u003e\n"],["\u003cp\u003eInput indices can be integers, ee.Number objects, or other computed objects that evaluate to an integer.\u003c/p\u003e\n"]]],[],null,["# ee.List.get\n\nReturns the element at the specified position in list. A negative index counts backwards from the end of the list.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|-------------------|---------|\n| List.get`(index)` | Object |\n\n| Argument | Type | Details |\n|--------------|---------|---------|\n| this: `list` | List | |\n| `index` | Integer | |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// An ee.List object.\nvar list = ee.List([5, 10, 15, 20, 25, 30]);\n\n// Fetch elements at specified 0-based positions in the list.\nprint('The second element', list.get(1));\nprint('The fourth element', list.get(3));\nprint('The last element', list.get(-1));\nprint('The second to last element', list.get(-2));\n\n// ee.Number and integer computed objects are valid inputs.\nprint('Computed object index input', list.get(list.get(0)));\n\n// The result of ee.List.get is an ambiguous object type. You need to cast the\n// result to the expected type to use it in subsequent instance methods. For\n// example, if you are fetching a number and wish to add it to another number,\n// you must cast the .get() result as an ee.Number.\nprint('Add fetched number to another number', ee.Number(list.get(1)).add(2));\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\n# An ee.List object.\nee_list = ee.List([5, 10, 15, 20, 25, 30])\n\n# Fetch elements at specified 0-based positions in the list.\nprint('The second element:', ee_list.get(1).getInfo())\nprint('The fourth element:', ee_list.get(3).getInfo())\nprint('The last element:', ee_list.get(-1).getInfo())\nprint('The second to last element:', ee_list.get(-2).getInfo())\n\n# ee.Number and integer computed objects are valid inputs.\nprint('Computed object index input:', ee_list.get(list.get(0)).getInfo())\n\n# The result of ee.List.get is an ambiguous object type. You need to cast the\n# result to the expected type to use it in subsequent instance methods. For\n# example, if you are fetching a number and wish to add it to another number,\n# you must cast the .get() result as an ee.Number.\nprint('Add fetched number to another number:',\n ee.Number(list.get(1)).add(2).getInfo())\n```"]]