我试图将图像放置在camera.py的网络摄像头提要上并发送到main.py; 输出显示在flask生成的本地服务器中。但是我遇到了以下错误
libv4l2: error setting pixformat: Device or resource busy
HIGHGUI ERROR: libv4l unable to ioctl S_FMT
libv4l2: error setting pixformat: Device or resource busy
libv4l1: error setting pixformat: Device or resource busy
HIGHGUI ERROR: libv4l unable to ioctl VIDIOCSPICT
我使用以下代码：
from flask import Flask, render_template, Response
from camera import VideoCamera
app = Flask(__name__)
@app.route('/')
def index():
return render_template('index.html')
def gen(camera):
while True:
frame = camera.get_frame()
yield (b'--frame\r\n'
b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n\r\n')
@app.route('/video_feed')
def video_feed():
return Response(gen(VideoCamera()), …我正在写一个连接4游戏,你可以在其中选择板的大小.对于大多数电路板尺寸而言,游戏可以完美运行,但是当电路板较高而宽度较大时,会给我带来问题.我不断得到索引超出范围错误,我不知道我做错了什么.就我的检查功能而言,这就是我现在所拥有的,因为它是唯一给我问题的部分.
def checkOWin(board):
boardHeight = len(board)
boardWidth = len(board[0])
tile = 'O'
# check horizontal spaces
for y in range(boardHeight):
for x in range(boardWidth - 3):
if board[x][y] == tile and board[x+1][y] == tile and board[x+2][y] == tile and board[x+3][y] == tile:
return True
# check vertical spaces
for x in range(boardWidth):
for y in range(boardHeight - 3):
if board[x][y] == tile and board[x][y+1] == tile and board[x][y+2] == tile and board[x][y+3] == tile:
return True
# check / diagonal …我知道如何编写 dll 以及如何编写服务以及如何使用 运行 dll rundll32，但现在我想编写一个在 Windows 中作为服务安装的 dll
我不知道这是否可能，或者应该导出 dll 中的哪个函数？
如何安装和运行 dll 作为服务？
例如:
if l.index(a)== -1:
l += [a]
如果我运行这样的东西,我将得到一个值错误.我假设这不是一个新问题.
更新:一旦我不知道3 %4 =0......
def gcd(a, b):
"""Calculate the Greatest Common Divisor of a and b.
Unless b==0, the result will have the same sign as b (so that when
b is divided by it, the result comes out positive).
"""
while b:
a, b = b, a%b
return a
我认为它的工作原理如下:
gcd(3,4) => while 4: => 3,4 = 4, 3%4 =>
我怎么能做这样的事情.
index=[[test1,test2,test3],[test4,test5,test6],[test7,test8,test9]]
if test5 is in index:
print True
我有以下列表理解.
return [tower for tower in state if tower != space else []]
但是当我运行它时,python吐出了这个错误:
return [tower for tower in state if tower != space else []]
^
SyntaxError: invalid syntax
如果我删除else语句,它运行正常.我是否以某种方式写错了其他声明？
我希望脚本的一部分是这样的.
if list[1] is in list.pop n times:
return True
我希望我写的一部分脚本可以做这样的事情.
x=0
y=0
list=[["cat","dog","mouse",1],["cat","dog","mouse",2],["cat","dog","mouse",3]]
row=list[y]
item=row[x]
print list.count(item)
问题是这将打印0,因为它不搜索单个列表.如何让它返回实例的总数？
import time
def average(numbers):
"Return the average (arithmetic mean) of a sequence of numbers."
return sum(numbers) / float(len(numbers))
#example function
def domath(a,b,c):
a+b+c
a*b*c
a/b/c
a-b-c
a^b
b^c
def timedcalls(n, fn, *args):
times=[]
if type(n)==int:
t0 = time.clock()
for rep in range(n):
t0 = time.clock()
fn(*args)
t1 = time.clock()
times.append(t1-t0)
else:
start=time.clock()
while time.clock-start<int(n):
t0 = time.clock()
fn(*args)
t1 = time.clock()
times.append(t1-t0)
return min(times), average(times), max(times)
print timedcalls(5.0, domath, 1,2,3)
这个代码适用于int类型,但出于某种原因,如果我使用浮点数,它会给我这个错误.
Traceback (most recent call last):
File "<stdin>", line 29, …我正在尝试用Java格式化两个数组来打印这样的东西:
Inventory Number Books Prices
------------------------------------------------------------------
1 Intro to Java $45.99
2 Intro to C++ $89.34
3 Design Patterns $100.00
4 Perl $25.00
我使用以下代码:
for(int i = 0; i < 4; i++) {
System.out.print(i+1);
System.out.print(" " + books[i] + " ");
System.out.print(" " + "$" + booksPrices[i] + " ");
System.out.print("\n");
}
但我得到这个格式不佳的结果:
Inventory Number Books Prices
------------------------------------------------------------------
1 Intro to Java $45.99
2 Intro to C++ $89.34
3 Design Patterns $100.0
4 Perl $25.0
我如何直接在顶部的标题下面排列所有列？
有没有更好的方法来做这个？