假设我们有一个数字 list(列表)以及一个生成这些数字的平方的 generator(生成器): >>> numbers = [1, 2, 3, 5, 7] >>> squares = (n**2 for n in numbers) 1. 2. 我们可以将我们的 generator 对象传给tuple构造函数来变成一个 tuple(元组): >>> tuple(squares) (1, 4, 9, 25, 49) 1....
for i in [0, 1, 2, 3]: print(i) 前面的for循环实际上遍历了它的子句,变量i在每次迭代中被设置为[0, 1, 2, 3]列表中的一个连续值。 一种常见的 Python 技术是使用range(len(someList))和for循环来迭代列表的索引。例如,在交互式 Shell 中输入以下内容: 代码语言:javascript 复制 >>> supplies ...
unpack:[2,7,4],"\u5b9e\u9645\u4e0a\u53ef\u4ee5\u662f\u4efb\u4f55\u5e8f\u5217":9,"\u5bf9\u5927\u591a\u6570\u7684\u5bf9\u8c61\u8fdb\u884c\u5f15\u7528\u8ba1\u6570\u548c\u5783\u573e\u56de\u6536":4,must:0,gallahad:0,"\u88ab\u5c01\u88c5\u8fdb\u5143\u7ec4":...
fori,(key,value)inenumerate(d.items()): print(i,key,value) 注意,键值周围的括号很重要,没有括号,您将得到一个ValueError"not enough values to unpack"。 Iterating over dictionaries using 'for' loops 1 2 3 d={'x':1,'y':2,'z':3} forkeyind: ... How does Python recognize that it ...
for i in lst: print(i) # python2.5 …… >>> source = open("demo3.py").read() >>> co = compile(source, "demo3.py", "exec") >>> import dis >>> dis.dis(co) 1 0 LOAD_CONST 0 (1) 3 LOAD_CONST 1 (2) 6 BUILD_LIST 2 9 STORE_NAME 0 (lst) 2 12 SETUP_LOOP 19 (...
for digit in [3,1,4,1,5,9]: print (digit) This will print: 3 1 4 1 5 9 If you are iterating through an object that yields containers or sequences, you can use Python’s multi-assignment syntax to unpack them. For instance: for letter, number in [["a",1],["b",2]]:...
loop[使用循环遍历获取前两个元素] unpack[使用解包操作符获取前两个元素] output[输出结果] end[结束] start --> input input --> slice input --> loop input --> unpack slice --> output loop --> output unpack --> output output --> end ...
As you can confirm in the loop’s output, all the items are tuples. Once you know this, you can use tuple unpacking to iterate through the keys and values in parallel.To achieve parallel iteration through keys and values, you just need to unpack the elements of every item into two ...
Method 1: If the loop body consists of one statement, simply write this statement into the same line:for i in range(10): print(i). Thisprintsthe first 10 numbers to the shell (from 0 to 9). Method 2:If the purpose of the loop is tocreate a list, uselist comprehensioninstead:squar...
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