如果指针存储变量的地址......那么我们从哪里得到指针?
我问的是,如果我们直接使用指针,那么必须有一个位置,我们得到这个指针?
我一直在寻找这个古老问题的最新解决方案.
长话短说我想用css + html - > pdf并用java做.
我不想使用API,因为数据是敏感的.谷歌搜索为我提供了无数的网站/服务提供这样做,但我正在寻找一个独立的工具,并寻找一个可以很好地从我的Java服务器工作.我发现这个看起来很棒的命令行工具,但它是一个命令行工具,并且Web服务器上的产生进程开始变得粗略IMO(但我总是愿意听到其他情况).此外,飞碟似乎是一个标准的选择,但我听到了混合的评论.
这是一个关于这个主题的5岁问题,但我认为事情已经改变了!特别是在使用dom操作的前端单元测试领域所做的所有工作中,我认为可能有一些比传统解决方案更少,我愿意全部听到它们!
任何帮助将不胜感激.
当记事本是我的.txt文件的默认程序时,如何告诉Windows在写字板中打开C:\ test\test.txt?
我一直在尝试运行此代码,这是错误
File "C:/hari/Academics/python/py programs/gui qt4/book/calculator.py", line 27, in updateUi
text = unicode(self.lineedit.text(),'utf-8')
NameError: name 'unicode' is not defined
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代码 :
from __future__ import division
from math import *
from PyQt4.QtGui import *
from PyQt4.QtCore import *
import sys
class Form(QDialog):
def __init__(self,parent =None):
super(Form,self).__init__(parent)
self.browser =QTextBrowser()
self.lineedit =QLineEdit("type an exp")
self.lineedit.selectAll()
layout=QVBoxLayout()
layout.addWidget(self.browser)
layout.addWidget(self.lineedit)
self.setLayout(layout)
self.lineedit.setFocus()
self.connect(self.lineedit, SIGNAL("returnPressed()"), self.updateUi)
self.setWindowTitle("Calculate")
def updateUi(self):
try:
text = unicode(self.lineedit.text())
print(type(text))
self.browser.append(text+" = <b>"+eval(text)+"</b>" )
except:
self.browser.append("<font color=red>"+ text + " is invalid</font>")
app=QApplication(sys.argv) …Run Code Online (Sandbox Code Playgroud) 我试图从使用Python 3中的正则表达式的文本文件中的wiki标题转储中提取英文标题.Wiki转储包含其他语言的标题和一些符号.以下是我的代码:
with open('/Users/some/directory/title.txt', 'rb')as f:
text=f.read()
letters_only = re.sub(b"[^a-zA-Z]", " ", text)
words = letters_only.lower().split()
print(words)
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但我收到一个错误:
TypeError: sequence item 1: expected a bytes-like object, str found
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在线: letters_only = re.sub(b"[^a-zA-Z]", " ", text)
但是,我使用b''输出作为字节类型,下面是文本文件的示例:
Destroy-Oh-Boy!!
!!Que_Corra_La_Voz!!
!!_(chess)
!!_(disambiguation)
!'O!Kung
!'O!Kung_language
!'O-!khung_language
!337$P34K
!=
!?
!?!
!?Revolution!?
!?_(chess)
!A_Luchar!
!Action_Pact!
!Action_pact!
!Adios_Amigos!
!Alabadle!
!Alarma!
!Alarma!_(album)
!Alarma!_(disambiguation)
!Alarma!_(magazine)
!Alarma!_Records
!Alarma!_magazine
!Alfaro_Vive,_Carajo!
!All-Time_Quarterback!
!All-Time_Quarterback!_(EP)
!All-Time_Quarterback!_(album)
!Alla_tu!
!Amigos!
!Amigos!_(Arrested_Development_episode)
!Arriba!_La_Pachanga
!Ask_a_Mexican!
!Atame!
!Ay,_Carmela!_(film)
!Ay,_caramba!
!BANG!
!Bang!
!Bang!_TV
!Basta_Ya!
!Bastardos!
!Bastardos!_(album) …Run Code Online (Sandbox Code Playgroud) 这是莫名其妙的后续这个问题
首先,你会注意到你不能sum在一个字符串列表上执行连接它们,python告诉你使用它str.join,这是一个很好的建议,因为无论你如何使用+字符串,性能都很糟糕.
"不能使用sum"限制不适用于list,但是,这itertools.chain.from_iterable是执行此类列表展平的首选方法.
但是sum(x,[])什么时候x列表清单肯定是坏的.
但是它应该保持这种状态吗?
我比较了3种方法
import time
import itertools
a = [list(range(1,1000)) for _ in range(1000)]
start=time.time()
sum(a,[])
print(time.time()-start)
start=time.time()
list(itertools.chain.from_iterable(a))
print(time.time()-start)
start=time.time()
z=[]
for s in a:
z += s
print(time.time()-start)
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结果:
sum()在列表中:10.46647310256958.好的,我们知道.itertools.chain:0.07705187797546387itertools.chain您看到的更快)所以sum落后了,因为它result = result + b代替了result += b
所以现在我的问题是:
为什么不能sum在可用时使用这种累积方法?
(这对于现有的应用程序来说是透明的,并且可以使用sum内置的内容来有效地压缩列表)
我导入的Python模块
import Queue
from threading import Thread
import time
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但是当我运行代码时
File "b1.py", line 3, in <module>
import Queue
ModuleNotFoundError: No module named 'Queue'
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我在SO上看过类似的帖子,但对我来说没有用
/usr/bin/python3 --version
Python 3.5.2
milenko@milenko-System-Product-Name:~$ python --version
Python 3.6.0 :: Anaconda custom (64-bit)
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如果我换到
from multiprocessing import Queue
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没有进口问题.但比我有这个
AttributeError: 'Queue' object has no attribute 'join'
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我接下来应该尝试什么?
如何修复Windows上的pip安装失败,错误如下.尝试安装ansible时出现此错误.
我怀疑选择的pip包安装问题.但同样适用于基于Linux的系统.pip安装的操作系统是否会有任何差异
Exception:
Traceback (most recent call last):
File "c:\python27\lib\site-packages\pip\basecommand.py", line 215, in main
status = self.run(options, args)
File "c:\python27\lib\site-packages\pip\commands\install.py", line 324, in run
requirement_set.prepare_files(finder)
File "c:\python27\lib\site-packages\pip\req\req_set.py", line 380, in prepare_files
ignore_dependencies=self.ignore_dependencies))
File "c:\python27\lib\site-packages\pip\req\req_set.py", line 620, in _prepare_file
session=self.session, hashes=hashes)
File "c:\python27\lib\site-packages\pip\download.py", line 821, in unpack_url
hashes=hashes
File "c:\python27\lib\site-packages\pip\download.py", line 663, in unpack_http_url
unpack_file(from_path, location, content_type, link)
File "c:\python27\lib\site-packages\pip\utils\__init__.py", line 605, in unpack_file
untar_file(filename, location)
File "c:\python27\lib\site-packages\pip\utils\__init__.py", line 553, in untar_file
ensure_dir(path)
File "c:\python27\lib\site-packages\pip\utils\__init__.py", line 83, in ensure_dir
os.makedirs(path)
File …Run Code Online (Sandbox Code Playgroud) 如何使用 python 读取 ZIP 文件注释?我尝试使用
import zipfile
archive = zipfile.ZipFile('D:\XXX\Desktop\MyZip.zip', 'r')
comment = archive.comment("firstobj.1")
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但它不起作用......任何帮助将不胜感激:)谢谢
我正在尝试通过 IFRAME 共享 Google 地图,但控制台中出现此错误
图书馆检索未知。请参阅https://developers.google.com/maps/documentation/javascript/libraries
<iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d2795.5423816131142!2d11.312607315808078!3d45.519289937786425!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x477f48c46ad35441%3A0x9a16514436b0fe8e!2sMarmi%20Zem%20di%20Ziche%20Enrico!5e0!3m2!1sit!2sit!4v1676708610573!5m2!1sit!2sit" width="600" height="450" style="border:0;" allowfullscreen="" loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe>
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<iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d2795.5423816131142!2d11.312607315808078!3d45.519289937786425!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x477f48c46ad35441%3A0x9a16514436b0fe8e!2sMarmi%20Zem%20di%20Ziche%20Enrico!5e0!3m2!1sit!2sit!4v1676708610573!5m2!1sit!2sit" width="600" height="450" style="border:0;" allowfullscreen="" loading="lazy" referrerpolicy="no-referrer-when-downgrade"></iframe>
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你知道为什么吗?
python ×5
python-3.x ×2
windows ×2
batch-file ×1
c ×1
converters ×1
google-maps ×1
html ×1
java ×1
list ×1
pdf ×1
performance ×1
pip ×1
pointers ×1
pyqt4 ×1
python-3.4 ×1
regex ×1
sum ×1
zip ×1