barcodelib.barcode.asp.net.dll download URL Anatomy in Font

Generating QR Code JIS X 0510 in Font URL Anatomy

URL Anatomy
QR Code JIS X 0510 Maker In None
Using Barcode creation for Font Control to generate, create QR Code ISO/IEC18004 image in Font applications.
www.OnBarcode.com
EAN13 Creator In None
Using Barcode encoder for Font Control to generate, create EAN13 image in Font applications.
www.OnBarcode.com
Before tackling the inner workings of HTTP, we should pause to settle a bit of terminology surrounding Uniform Resource Locators (URLs), the wonderful strings that tell your web browser how to fetch resources from the World Wide Web. They are a subclass of the full set of possible Uniform Resource Identifiers (URIs); specifically, they are URIs constructed so that they give instructions for fetching a document, instead of serving only as an identifier. For example, consider a very simple URL like the following: http://python.org If submitted to a web browser, this URL is interpreted as an order to resolve the host name python.org to an IP address (see 4), make a TCP connection to that IP address at the standard HTTP port 80 (see 3), and then ask for the root document / that lives at that site. Of course, many URLs are more complicated. Imagine, for example, that there existed a service offering pre-scaled thumbnail versions of various corporate logos for an international commerce site we were writing. And imagine that we wanted the logo for Nord/LB, a large German bank. The resulting URL might look something like this: http://example.com:8080/Nord%2FLB/logo shape=square&dpi=96
Painting Code 3 Of 9 In None
Using Barcode creator for Font Control to generate, create Code 3/9 image in Font applications.
www.OnBarcode.com
Encode UPC Code In None
Using Barcode generation for Font Control to generate, create UPC A image in Font applications.
www.OnBarcode.com
CHAPTER 9 HTTP
Making UCC.EAN - 128 In None
Using Barcode generation for Font Control to generate, create EAN / UCC - 14 image in Font applications.
www.OnBarcode.com
Encoding Barcode In None
Using Barcode generation for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Here, the URL specifies more information than our previous example did: The protocol will, again, be HTTP. The hostname example.com will be resolved to an IP. This time, port 8080 will be used instead of 80. Once a connection is complete, the remote server will be asked for the resource named:
PDF417 Drawer In None
Using Barcode creator for Font Control to generate, create PDF-417 2d barcode image in Font applications.
www.OnBarcode.com
MSI Plessey Encoder In None
Using Barcode creation for Font Control to generate, create MSI Plessey image in Font applications.
www.OnBarcode.com
/Nord%2FLB/logo shape=square&dpi=96 Web servers, in practice, have absolute freedom to interpret URLs as they please; however, the intention of the standard is that this URL be parsed into two question-mark-delimited pieces. The first is a path consisting of two elements: A Nord/LB path element. A logo path element.
Printing QR In None
Using Barcode creator for Font Control to generate, create QR-Code image in Font applications.
www.OnBarcode.com
Scan QR Code 2d Barcode In C#
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
The string following the is interpreted as a query containing two terms: A shape parameter whose value is square. A dpi parameter whose value is 96.
PDF 417 Creation In None
Using Barcode maker for Office Excel Control to generate, create PDF417 image in Excel applications.
www.OnBarcode.com
Code 39 Full ASCII Creation In None
Using Barcode creation for Word Control to generate, create Code-39 image in Word applications.
www.OnBarcode.com
Thus can complicated URLs be built from simple pieces. Any characters beyond the alphanumerics, a few punctuation marks specifically the set $_.+!*'(), and the special delimiter characters themselves (like the slashes) must be percent-encoded by following a percent sign % with the two-digit hexadecimal code for the character. You have probably seen %20 used for a space in a URL, for example, and %2F when a slash needs to appear. The case of %2F is important enough that we ought to pause and consider that last URL again. Please note that the following URL paths are not equivalent: Nord%2FLB%2Flogo Nord%2FLB/logo Nord/LB/logo These are not three versions of the same URL path! Instead, their respective meanings are as follows: A single path component, named Nord/LB/logo. Two path components, Nord/LB and logo. Three separate path components Nord, LB, and logo.
Code 3 Of 9 Scanner In Visual Studio .NET
Using Barcode decoder for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Data Matrix ECC200 Generation In Java
Using Barcode generator for BIRT reports Control to generate, create DataMatrix image in BIRT applications.
www.OnBarcode.com
These distinctions are especially crucial when web clients parse relative URLs, which we will discuss in the next section. The most important Python routines for working with URLs live, appropriately enough, in their own module: >>> from urlparse import urlparse, urldefrag, parse_qs, parse_qsl At least, the functions live together in recent versions of Python for versions of Pythons older than 2.6, two of them live in the cgi module instead: # For Python 2.5 and earlier >>> from urlparse import urlparse, urldefrag >>> from cgi import parse_qs, parse_qsl
EAN-13 Decoder In VS .NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
DataBar Drawer In Java
Using Barcode generator for Java Control to generate, create GS1 DataBar Expanded image in Java applications.
www.OnBarcode.com
CHAPTER 9 HTTP
Code 128 Decoder In VB.NET
Using Barcode decoder for Visual Studio .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Creating Code 128 Code Set B In Java
Using Barcode generator for Java Control to generate, create Code 128 Code Set C image in Java applications.
www.OnBarcode.com
With these routines, you can get large and complex URLs like the example given earlier and turn them into their component parts, with RFC-compliant parsing already implemented for you: >>> p = urlparse('http://example.com:8080/Nord%2FLB/logo shape=square&dpi=96') >>> p ParseResult(scheme='http', netloc='example.com:8080', path='/Nord%2FLB/logo', params='', query='shape=square&dpi=96', fragment='') The query string that is offered by the ParseResult can then be submitted to one of the parsing routines if you want to interpret it as a series of key-value pairs, which is a standard way for web forms to submit them: >>> parse_qs(p.query) {'shape': ['square'], 'dpi': ['96']} Note that each value in this dictionary is a list, rather than simply a string. This is to support the fact that a given parameter might be specified several times in a single URL; in such cases, the values are simply appended to the list: >>> parse_qs('mode=topographic&pin=Boston&pin=San%20Francisco') {'mode': ['topographic'], 'pin': ['Boston', 'San Francisco']} This, you will note, preserves the order in which values arrive; of course, this does not preserve the order of the parameters themselves because dictionary keys do not remember any particular order. If the order is important to you, then use the parse_qsl() function instead (the l must stand for list ): >>> parse_qsl('mode=topographic&pin=Boston&pin=San%20Francisco') [('mode', 'topographic'), ('pin', 'Boston'), ('pin', 'San Francisco')] Finally, note that an anchor appended to a URL after a # character is not relevant to the HTTP protocol. This is because any anchor is stripped off and is not turned into part of the HTTP request. Instead, the anchor tells a web client to jump to some particular section of a document after the HTTP transaction is complete and the document has been downloaded. To remove the anchor, use urldefrag(): >>> u = 'http://docs.python.org/library/urlparse.html#urlparse.urldefrag' >>> urldefrag(u) ('http://docs.python.org/library/urlparse.html', 'urlparse.urldefrag') You can turn a ParseResult back into a URL by calling its geturl() method. When combined with the urlencode() function, which knows how to build query strings, this can be used to construct new URLs: >>> import urllib, urlparse >>> query = urllib.urlencode({'company': 'Nord/LB', 'report': 'sales'}) >>> p = urlparse.ParseResult( ... 'https', 'example.com', 'data', None, query, None) >>> p.geturl() 'https://example.com/data report=sales&company=Nord%2FLB' Note that geturl() correctly escapes all special characters in the resulting URL, which is a strong argument for using this means of building URLs rather than trying to assemble strings correctly by hand.
Code 3/9 Creator In None
Using Barcode creation for Online Control to generate, create USS Code 39 image in Online applications.
www.OnBarcode.com
Reading Barcode In Visual Basic .NET
Using Barcode Control SDK for .NET framework Control to generate, create, read, scan barcode image in .NET applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.