AllowQuerySemicolons returns a handler that serves requests by converting any unescaped semicolons in the URL query to ampersands, and invoking the handler h. This restores the pre-Go 1. See golang. Note that this behavior doesn't match that of many proxies, and the mismatch can lead to security issues. FileServer returns a handler that serves HTTP requests with the contents of the file system rooted at root. RedirectHandler returns a request handler that redirects each request it receives to the given url using the given status code.
StripPrefix handles a request for a path that doesn't begin with prefix by replying with an HTTP not found error. The prefix must match exactly: if the prefix in the request contains escaped characters the reply is also an HTTP not found error. The new Handler calls h. ServeHTTP to handle each request, but if a call runs for longer than its time limit, the handler responds with a Service Unavailable error and the given message in its body.
If msg is empty, a suitable default message will be sent. TimeoutHandler supports the Pusher interface but does not support the Hijacker or Flusher interfaces. If f is a function with the appropriate signature, HandlerFunc f is a Handler that calls f.
Add adds the key, value pair to the header. It appends to any existing values associated with key. The key is case insensitive; it is canonicalized by CanonicalHeaderKey. Del deletes the values associated with key. Get gets the first value associated with the given key. If there are no values associated with the key, Get returns "".
It is case insensitive; textproto. To use non-canonical keys, access the map directly. Set sets the header entries associated with key to the single element value. It replaces any existing values associated with key. The key is case insensitive; it is canonicalized by textproto. To use non-canonical keys, assign to the map directly.
Values returns all values associated with the given key. The returned slice is not a copy. WriteSubset writes a header in wire format. Keys are not canonicalized before checking the exclude map. ResponseWriter wrappers may also not support Hijacker. Deprecated: Not all errors in the http package related to protocol errors are of type ProtocolError. The field semantics differ slightly between client and server usage. In addition to the notes on the fields below, see the documentation for Request.
Write and RoundTripper. If the provided body is also an io. Closer, the returned Request. Do or Transport. For an outgoing client request, the context controls the entire lifetime of a request and its response: obtaining a connection, sending the request, and reading the response headers and body.
See the Request type's documentation for the difference between inbound and outbound request fields. Reader, the returned request's ContentLength is set to its exact value instead of -1 , GetBody is populated so and redirects can replay the body , and Body is set to NoBody if the ContentLength is 0.
ReadRequest is a low-level function and should only be used for specialized applications; most code should use the Server to read requests and handle them via the Handler interface. AddCookie adds a cookie to the request. Per RFC section 5. That means all cookies, if any, are written into the same line, separated by semicolon. AddCookie only sanitizes c's name and value, and does not sanitize a Cookie header already present in the request. See RFC , Section 2. Clone returns a deep copy of r with its context changed to ctx.
The provided ctx must be non-nil. Cookie returns the named cookie provided in the request or ErrNoCookie if not found.
If multiple cookies match the given name, only one cookie will be returned. FormFile returns the first file for the provided form key. FormValue returns the first value for the named component of the query. If key is not present, FormValue returns the empty string. To access multiple values of the same key, call ParseForm and then inspect Request. Form directly. Use this function instead of ParseMultipartForm to process the request body as a stream. PostForm and r. Request body parameters take precedence over URL query string values in r.
PostForm is initialized to a non-nil, empty value. The whole request body is parsed and up to a total of maxMemory bytes of its file parts are stored in memory, with the remainder stored on disk in temporary files. ParseMultipartForm calls ParseForm if necessary.
If ParseForm returns an error, ParseMultipartForm returns it but also continues parsing the request body.
After one call to ParseMultipartForm, subsequent calls have no effect. URL query parameters are ignored. If key is not present, PostFormValue returns the empty string. Referer is misspelled as in the request itself, a mistake from the earliest days of HTTP. This value can also be fetched from the Header map as Header["Referer"]; the benefit of making it available as a method is that the compiler can diagnose programs that use the alternate correct English spelling req.
Referrer but cannot diagnose programs that use Header["Referrer"]. Some protocols may impose additional requirements on pre-escaping the username and password. WithContext returns a shallow copy of r with its context changed to ctx. For outgoing client request, the context controls the entire lifetime of a request and its response: obtaining a connection, sending the request, and reading the response headers and body. To create a new request with a context, use NewRequestWithContext.
To change the context of a request, such as an incoming request you want to modify before sending back out, use Request. Between those two uses, it's rare to need WithContext.
This method consults the following fields of the request:. Body is closed after it is sent. In either case, WriteProxy also writes a Host header, using either r. Host or r. The Client and Transport return Responses from servers once the response headers have been received.
The response body is streamed on demand as the Body field is read. If the response is one of the following redirect codes, Get follows the redirect, up to a maximum of 10 redirects:. An error is returned if there were too many redirects or if there was an HTTP protocol error. To make a request with a specified context. If the response is one of the following redirect codes, Head follows the redirect, up to a maximum of 10 redirects:. To set other headers, use NewRequest and DefaultClient.
The req parameter optionally specifies the Request that corresponds to this Response. If nil, a GET request is assumed. Clients must call resp. Close when finished reading resp. After that call, clients can inspect resp. Location returns the URL of the response's "Location" header, if present.
Relative redirects are resolved relative to the Response's Request. ErrNoLocation is returned if no Location header is present. RoundTripper is an interface representing the ability to execute a single HTTP transaction, obtaining the Response for a given Request.
DefaultTransport is the default implementation of Transport and is used by DefaultClient. It establishes network connections as needed and caches them for reuse by subsequent calls. The returned RoundTripper ignores the URL host in its incoming requests, as well as most other properties of the request. The typical use case for NewFileTransport is to register the "file" protocol with a Transport, as in:.
SameSite allows a server to define a cookie attribute making it impossible for the browser to send this cookie along with cross-site requests. The main goal is to mitigate the risk of cross-origin information leakage, and provide some protection against cross-site request forgery attacks. It matches the URL of each incoming request against a list of registered patterns and calls the handler for the pattern that most closely matches the URL.
If a subtree has been registered and a request is received naming the subtree root without its trailing slash, ServeMux redirects that request to the subtree root adding the trailing slash. This behavior can be overridden with a separate registration for the path without the trailing slash.
Patterns may optionally begin with a host name, restricting matches to URLs on that host only. ServeMux also takes care of sanitizing the URL request path and the Host header, stripping the port number and redirecting any request containing.
Handle registers the handler for the given pattern. If a handler already exists for pattern, Handle panics. Handler returns the handler to use for the given request, consulting r. Method, r. Host, and r. It always returns a non-nil handler. If the path is not in its canonical form, the handler will be an internally-generated handler that redirects to the canonical path. If the host contains a port, it is ignored when matching handlers. Handler also returns the registered pattern that matches the request or, in the case of internally-generated redirects, the pattern that will match after following the redirect.
The zero value for Server is a valid configuration. Close immediately closes all active net. For a graceful shutdown, use Shutdown.
Close does not attempt to close and does not even know about any hijacked connections, such as WebSockets. Addr and then calls Serve to handle requests on incoming connections. ListenAndServe always returns a non-nil error.
Filenames containing a certificate and matching private key for the server must be provided if neither the Server's TLSConfig. Certificates nor TLSConfig. GetCertificate are populated. RegisterOnShutdown registers a function to call on Shutdown. This can be used to gracefully shutdown connections that have undergone ALPN protocol upgrade or that have been hijacked.
This function should start protocol-specific graceful shutdown, but should not wait for shutdown to complete. Serve accepts incoming connections on the Listener l, creating a new service goroutine for each.
The service goroutines read requests and then call srv. Handler to reply to them. Serve always returns a non-nil error and closes l. ServeTLS accepts incoming connections on the Listener l, creating a new service goroutine for each. The service goroutines perform TLS setup and then read requests, calling srv. Files containing a certificate and matching private key for the server must be provided if neither the Server's TLSConfig.
ServeTLS always returns a non-nil error. By default, keep-alives are always enabled. Only very resource-constrained environments or servers in the process of shutting down should disable them. Shutdown gracefully shuts down the server without interrupting any active connections. Shutdown works by first closing all open listeners, then closing all idle connections, and then waiting indefinitely for connections to return to idle and then shut down.
If the provided context expires before the shutdown is complete, Shutdown returns the context's error, otherwise it returns any error returned from closing the Server's underlying Listener s. Make sure the program doesn't exit and waits instead for Shutdown to return. Shutdown does not attempt to close nor wait for hijacked connections such as WebSockets.
The caller of Shutdown should separately notify such long-lived connections of shutdown and wait for them to close, if desired. See RegisterOnShutdown for a way to register shutdown notification functions. Once Shutdown has been called on a server, it may not be reused; future calls to methods such as Serve will return ErrServerClosed. By default, Transport caches connections for future re-use. This may leave many open connections when accessing many hosts. Transports should be reused instead of created as needed.
Creating a scatter plot is exactly the same as making a line plot but you call ax. If you sample a normal distribution and create a 3D plot from it, you get a ball of points with the majority focused around the center and less and less the further from the center you go.
First, I imported the python random module and set the seed so that you can reproduce my results. Next, I used three list comprehensions to create 3 x samples of a normal distribution using the random.
Then I set up the Figure and Axes as normal and made my plot by calling ax. In this example, I plotted the same X , Y and Z lists as in the very first example. I want to highlight to you that some of the points are darker and some are more transparent — this indicates depth. The ones that are darker in color are in the foreground and those further back are more see-through. If you plot this in IPython or an interactive Jupyter Notebook window and you rotate the plot, you will see that the transparency of each point changes as you rotate.
This lets you manually rotate them by clicking and dragging. If you right-click and move the mouse, you will zoom in and out of the plot. To save a static version of the plot, click the save icon. It is possible to rotate plots and even create animations via code but that is out of the scope of this article. Setting axis labels for 3D plots is identical for 2D plots except now there is a third axis — the z-axis — you can label.
You may notice that the axis labels are not particularly visible using the default settings. You can solve this by manually increasing the size of the Figure with the figsize argument in your plt. So, I much prefer method 2.
Much better! Firstly, because you increased the size of the Figure , all the axis labels are clearly visible. Plus, it only took you one line of code to label them all. In general, if you ever use a ax. This saves you space and is nicer to type, especially if you want to make numerous modifications to the graph such as also adding a title. You add legends to 3D plots in the exact same way you add legends to any other plots.
Use the label keyword argument and then call ax. In this example, I first set the random seed to 1 so that you can reproduce the same results as me. I set up the Figure and Axes as expected, made my first 3D plot using X , Y and Z and labeled it with the label keyword argument and an appropriate string.
To save me from manually creating a brand new dataset, I thought it would be a good idea to make use of the data I already had. So, I applied the random. So, calling ax. Finally, I labeled the second plot and called ax.
All the usual things you can do with legends are still possible for 3D plots. If you want to learn more than these basic steps, check out my comprehensive guide to legends in matplotlib. Note: If you run the above code again, you will get a different looking plot. This is because you will start with the shuffled X , Y and Z lists rather than the originals you created further up inb the post.
There are two backgrounds you can modify in matplotlib — the Figure and the Axes background. Both can be set using either the. Hopefully, you know by now that I much prefer the second method over the first!
The first three lines are the same as a simple line plot. Then I called ax. In an example with one Axes , it looks a bit odd to set the Figure and Axes colors separately. If you have more than one Axes object, it looks much better. In this example, I used plt. For more info on using plt. Then I created the list colors containing 4 matplotlib color strings.
After that, I used a for loop to iterate over colors and axes. In order to iterate over colors and axes together, they need to be the same shape. There are several ways to do this but using the. Finally, I made the same plot on each Axes and set the facecolors. It is clear now why setting a Figure color can be more useful if you create subplots — there is more space for the color to shine through.
Try It Yourself on our interactive Python shell and check out the file 'plot. But first, note that your plots may look different to mine because I use the seaborn style throughout. You can set this by installing the seaborn library and calling the set function at the top of your code. The four steps needed to create advanced 3D plots are the same as those needed to create basic ones.
The most difficult part of creating surface and wireframe plots is step 3: getting 3D data. Matplotlib actually includes a helper function axes3d. It accepts a float and, for best results, choose a value between 0 and 1.
It always produces the same plot, but different floats give you different sized data and thus impact how detailed the plot is. At the end of step 3, you want to have three numpy arrays X , Y and Z , which you will pass to ax. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Feedback will be sent to Microsoft: By pressing the submit button, your feedback will be used to improve Microsoft products and services.
Privacy policy. You use a lambda expression to create an anonymous function. A lambda expression can be of any of the following two forms:. Expression lambda that has an expression as its body:. Statement lambda that has a statement block as its body:. To create a lambda expression, you specify input parameters if any on the left side of the lambda operator and an expression or a statement block on the other side.
Any lambda expression can be converted to a delegate type. The delegate type to which a lambda expression can be converted is defined by the types of its parameters and return value.
If a lambda expression doesn't return a value, it can be converted to one of the Action delegate types; otherwise, it can be converted to one of the Func delegate types. Expression lambdas can also be converted to the expression tree types, as the following example shows:. You can use lambda expressions in any code that requires instances of delegate types or expression trees, for example as an argument to the Task. Run Action method to pass the code that should be executed in the background.
When you use method-based syntax to call the Enumerable. Select method in the System. When you call the Queryable. In both cases, you can use the same lambda expression to specify the parameter value.
That makes the two Select calls to look similar although in fact the type of objects created from the lambdas is different. An expression lambda returns the result of the expression and takes the following basic form:. The body of an expression lambda can consist of a method call. However, if you're creating expression trees that are evaluated outside the context of the. The methods will have no meaning outside the context of the. A statement lambda resembles an expression lambda except that its statements are enclosed in braces:.
The body of a statement lambda can consist of any number of statements; however, in practice there are typically no more than two or three. You enclose input parameters of a lambda expression in parentheses. Specify zero input parameters with empty parentheses:. Sometimes the compiler can't infer the types of input parameters. You can specify the types explicitly as shown in the following example:. Input parameter types must be all explicit or all implicit; otherwise, a CS compiler error occurs.
Beginning with C 9. Lambda discard parameters may be useful when you use a lambda expression to provide an event handler. You can easily create lambda expressions and statements that incorporate asynchronous processing by using the async and await keywords. For example, the following Windows Forms example contains an event handler that calls and awaits an async method, ExampleMethodAsync.
You can add the same event handler by using an async lambda.
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