Python For loop not iterating over list (sys.argv) - 腾讯云开发者社区

文章/答案/技术大牛

发布

libuv源码阅读(12)--change

{ RB_ENTRY(watcher_list) entry; QUEUE watchers; int iterating; char* path; int wd; }; struct...watcher_list* w, uv_loop_t* loop) { /* if the watcher_list->watchers is being iterated over, we can't...* So, we use QUEUE_MOVE() trick to safely iterate over the queue....* And we don't free the watcher_list until we're done iterating...., time to (maybe) free empty watcher_list */ w->iterating = 0; maybe_free_watcher_list(w,

8321 0

英文阅读 | range对象不是迭代器

actual iterating....You can get an iterator from any iterable in Python by using the iter function: >>> iter([1, 2]) list_iterator...So after you’ve looped over an iterator once, it’ll be empty if you try to loop over it again: >>> my_iterator...They’re “lazy” because they have the ability to only compute items as you loop over them....If you know the thing you’re looping over happens to compute things as you loop over it, it’s a lazy

1.2K4 0

您找到你想要的搜索结果了吗？

是的

没有找到

Python3.8 了解的差不多了吧，Python3.9 新特性了解一下！

2、Python 现在获取在命令行上指定的脚本文件名的绝对路径（例如：python script.py：__main__ 模块的 __file__ 属性，sys.argv[0] 和 sys.path[0.../python3 script.py 结果 __file__='/Users/chenxiangan/cpython/script.py' sys.argv=['/Users/chenxiangan/...") 输出 haha over asyncio loop.shutdown_default_executor() 调度默认执行程序的关闭，并等待它连接ThreadPoolExecutor中的所有线程。...loop.set_default_executor(executor) 将executor设置为executor()中的run使用的默认执行程序。...移除 ElementTree 中在 Python3.2 就已经废弃的方法，getchildren() 和 getiterator()，以 list() 和 iter() 代替。

1.3K2 0

Python3.8 了解的差不多了吧，3.9 新特性了解一下

Python 现在获取在命令行上指定的脚本文件名的绝对路径（例如：python script.py：__main__ 模块的 __file__ 属性，sys.argv[0] 和 sys.path[0].../python3 script.py 结果： __file__='/Users/chenxiangan/cpython/script.py' sys.argv=['/Users/chenxiangan...") 输出： haha over 2. asyncio loop.shutdown_default_executor() 调度默认执行程序的关闭，并等待它连接ThreadPoolExecutor中的所有线程...loop.set_default_executor(executor) 将executor设置为executor()中的run使用的默认执行程序。...移除 ElementTree 中在 Python3.2 就已经废弃的方法，getchildren() 和 getiterator()，以 list() 和 iter() 代替。

3.2K2 0

python 快速入门

len(xing)): print (i, xing[i]) for i in range(1, 5): print i else: print 'The for loop...is over' while True: s = raw_input('Enter something : ') if s == 'quit': break ...=['a','b','c','d'] d = {} list2=[24, 53, 26, 9] i=0 while i list1) : d[list1[i]]=list2...print(a)'' 引用计算单词数目 import sys import string #import collections if len(sys.argv... strip = string.whitespace + string.punctuation + string.digits + "\"'" for filename in sys.argv

5703 0

Python3.8 了解的差不多了吧，Python3.9 新特性了解一下！

2K3 0

Python3.8 了解的差不多了吧，Python3.9 新特性了解一下！

1.2K4 0

R Programming week2 Control Structures

Common structures are： if, else: testing a condition for: execute a loop a fixed number of times while...: execute a loop while a condition istrue repeat: execute an infinite loop break: break the execution...of a loop next: skip an interation of a loop return: exit a function Most control structures are not...For loops are mostcommonly used for iterating over the elements of an object (list, vector, etc.) for...(iin 1:10) { print(i) } This loop takes the i variable and in eachiteration of the loop gives it values

4862 0

Github项目|几行代码即可实现人脸检测、目标检测的开源计算机视觉库

注意：目前仅在 Python 3.x 版本测试通过，而 2.x 版本并没有进行测试，所以建议在 Python 3.x 环境使用该库。...代码示例： import cvlib as cv import sys import cv2 import os # read input image image = cv2.imread(sys.argv...apply face detection faces, confidences = cv.detect_face(image) print(faces) print(confidences) # loop...[1]) # apply face detection face, conf = cv.detect_face(img) # loop through detected faces for f in...face: (startX,startY) = f[0],f[1] (endX,endY) = f[2],f[3] # draw rectangle over face

1.9K4 0

Python面试题目之深浅拷贝浅析

这里只说 Python，其他语言不了解。 Python 的 copy 模块中的 copy() method 其实是与 deep copy 相对的 shallow copy。...中套着 list 的情况，shallow copy 中的子list，并未从原 object 真的「独立」出来。...Python 与众不同的变量储存方法 Python 存储变量的方法跟其他 OOP 语言不同。它与其说是把值赋给变量，不如说是给变量建立了一个到具体值的 reference。...这种情况下，最好先建立一个 copy 出来： If you need to modify the sequence you are iterating over while inside the loop...Iterating over a sequence does not implicitly make a copy.

9813 0

pylint在pycharm的使用及pylint的配置

, zip-builtin-not-iterating, range-builtin-not-iterating, filter-builtin-not-iterating..., dict-keys-not-iterating, dict-values-not-iterating, deprecated-operator-function...To make it working # install python-enchant package.....implicit-str-concat-in-sequence should # generate a warning on implicit string concatenation in sequences defined over...# several lines.不理解 check-str-concat-over-line-jumps=no [TYPECHECK] # List of decorators that produce

9.8K3 0

Pandas字符串操作的各种方法速度测试

data.at[row ,'newcol'] = process(data.at[row, 'job'], data.at[row, 'company']) # 451 ms ± 34 ms per loop...(mean ± std. dev. of 7 runs, 1 loop each) # loop (mean ± std. dev.... of 7 runs, 1 loop each)> 完整的函数调用 m = "Iterating over the rows" add_to_df(n = n, m = m, x = vars(_...List-map似乎以N的平方根的速度增长使用fstring: c = f " {a}{b} " 使用fstring，结果很有趣，有的结果无法解释。...3、列表推导式就像它的名字一样，它还是一个list 4、还有一些奇怪的无法解释的问题，但是大部分的情况都是可以解释的如果你有更好的理解，欢迎留言作者：Dr. Mandar Karhade

6144 0

【Python】基础：数据读写与分析

Python数据分析介绍 Python适合用来做数据分析。...首先，确认安装好Python环境，首先复习Python语法基础： #!...print("Output #127: {}".format(x*x)) else: print("Output #128: x is not greater than 4") # for loop.../usr/bin/env python3 import sys input_file = sys.argv[1] output_file = sys.argv[2] with open(input_file.../usr/bin/env python3 import csv import sys input_file = sys.argv[1] output_file = sys.argv[2] with

2921 0

Yet Another Intro for Symbol

offers an unified interface for different data structures to access their elements, and can be iterated over...And it's a method that returns the default AsyncIterator for an object, only used by the brand new loop...statement for await...of, I'll illustrate in an example: // iterating over async iterables class List...false, value: this.xs[index++]}) } } } } constructor(private xs: T[]){} } // iterating...over async generator class List { // instance method async *[Symbol.iterator]() { for (let

7192 0

python learn 01 bas

Python Learn Part More_Info Content List 1.Python Introduce 1.1 python REPL 1.2 python helloworld.py...higher than that' else: print 'No, it is a little lower than that' else: print 'The while loop...is over...sys.argv: print i print '\n\nThe PYTHONPATH is', sys.path, '\n' 4.2 from..import yourself module...4.4 dir() $ python >>> import sys >>> dir(sys) # get list of attributes for sys module ['__displayhook

3941 0

Python & Async Simplified

can write basic code as normal, but as soon as you call a function, you have the potential to switch over...Luckily, Python has a built in statement to give a coroutine to the event loop and get the result back...list of paused coroutines so something else can run....The event loop is really what makes everything possible, and without it, async Python would just be a...Iterating over a Django QuerySet in an async function is going to do blocking synchronous operations

6172 0

python 查找文件脚本 find.py

/usr/bin/python """ ################################################################################...find module in the standard library: import as "PP4E.Tools.find"; like original, but uses os.walk loop...that uses the os.walk() generator to yield just matching filenames: use findlist() to force results list...(thisDir, name) yield fullpath def findlist(pattern, startdir=os.curdir, dosort=False): matches = list...[1], sys.argv[2] for name in find(namepattern, startdir): print(name)

5992 0

用 Python 帮运营妹纸快速搞定 Excel 文档

Python 处理 Excel 的第三方库您可以使用 Python 创建、读取和编写 Excel 电子表格。但是，Python 的标准库不支持使用 Excel，为此您需要安装第三方软件包。...创建一个名为iterating_over_cells.py的新文件，并向其中写入以下代码： # iterating_over_cells.py from openpyxl import load_workbook...继续创建一个名为iterating_over_cell_values.py的新文件，并将以下代码添加到其中： # iterating_over_cell_values.py from openpyxl...import load_workbook def iterating_over_values(path): workbook = load_workbook(filename=path)...max_col=3, values_only=True, ): print(value) if __name__ == '__main__': iterating_over_values

6.8K2 0

一步步理解python的异步IO

但是python的线程是有问题的，因为一个python进程中，同一时刻只允许一个线程运行，正在执行的线程会获取到GPL。...,w_list,e_list = select.select(inputs,outputs, ()) for i in w_list: # print(type(i)...while True: r_list,w_list,e_list = select.select(inputs,outputs, ()) for i in w_list: .../usr/bin/env python# encoding: utf-8 import asyncioimport aiohttpimport sys host = 'http://www.baidu.com'loop...= asyncio.get_event_loop()async def fetch(url): async with aiohttp.ClientSession(loop=loop) as session

6402 0

一步步理解python的异步IO

但是python的线程是有问题的，因为一个python进程中，同一时刻只允许一个线程运行，正在执行的线程会获取到GPL。...具体实现如下： import select import socket import time import sys num = int(sys.argv[1]) def coroutine():...,w_list,e_list = select.select(inputs,outputs, ()) for i in w_list: # print(type(...while True: r_list,w_list,e_list = select.select(inputs,outputs, ()) for i in w_list:...' loop = asyncio.get_event_loop() async def fetch(url): async with aiohttp.ClientSession(loop=loop

4172 0

点击加载更多

libuv源码阅读(12)--change

英文阅读 | range对象不是迭代器

Python3.8 了解的差不多了吧，Python3.9 新特性了解一下！

Python3.8 了解的差不多了吧，3.9 新特性了解一下

python 快速入门

Python3.8 了解的差不多了吧，Python3.9 新特性了解一下！

Python3.8 了解的差不多了吧，Python3.9 新特性了解一下！

R Programming week2 Control Structures

Github项目|几行代码即可实现人脸检测、目标检测的开源计算机视觉库

Python面试题目之深浅拷贝浅析

pylint在pycharm的使用及pylint的配置

Pandas字符串操作的各种方法速度测试

【Python】基础：数据读写与分析

Yet Another Intro for Symbol

python learn 01 bas

Python & Async Simplified

python 查找文件脚本 find.py

用 Python 帮运营妹纸快速搞定 Excel 文档

一步步理解python的异步IO

一步步理解python的异步IO

相关资讯

热门标签

活动推荐

运营活动

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐