Accessing data from a web API in Python
The key to using Python to call the Web API to obtain data is to master the basic processes and common tools. 1. Using requests to initiate HTTP requests is the most direct way. Use the get method to obtain the response and use json() to parse the data; 2. For APIs that need authentication, you can add tokens or keys through headers; 3. You need to check the response status code, and it is recommended to use response.raise_for_status() to automatically handle exceptions; 4. Facing the paging interface, you can request different pages in turn and add delays to avoid frequency limitations; 5. When processing the returned JSON data, you need to extract information according to the structure, and complex data can be converted into DataFrame to facilitate analysis. The entire process requires attention to error handling, paging logic and data analysis methods.
Calling the Web API to get data is actually quite common in Python, especially when doing data analysis or developing applications. The key is to understand the basic process and master several common tools.

The most direct way to initiate a request
requests is one of the most commonly used libraries in Python, used to send HTTP requests to get response content. It is simple and intuitive to use, for example, you want to use a public API (for example, //m.sbmmt.com/link/ :
import requests response = requests.get('https://api.example.com/data') data = response.json()
It should be noted that not all APIs are accessed without thresholds. Some of them require you to bring a token or key, you can write this way:

headers = {'Authorization': 'Bearer your_token_here'} response = requests.get('https://api.example.com/data', headers=headers)
If the returned status code is not 200, it means that an error may have occurred. It is best to make a judgment at this time to avoid errors in subsequent processing:
- Check
response.status_code
- Or use
response.raise_for_status()
to automatically throw an exception
Some APIs require paging or multiple requests
Many Web APIs do not return all data at once, but limit the number of returned each time through a paging mechanism. For example, an interface only returns 100 records by default, and if you want to get more, you have to turn the page.

The common way is to control the parameters, such as page=2
or offset=100
. You can use loops to continuously get until there is no new data:
all_data = [] page = 1 While True: url = f'https://api.example.com/data?page={page}' response = requests.get(url) data = response.json() if not data: break all_data.extend(data) page = 1
However, be careful not to request in a continuous manner too quickly. Some APIs have frequency limits. It is recommended to add a short pause, such as time.sleep(1)
.
The returned data structure must be processed by itself
The API usually returns data in JSON format. Python can be automatically converted into a dictionary or list using the .json()
method. But the specific value depends on the structure.
For example, sometimes the data is hidden deeper, like this:
{ "meta": { ... }, "results": [ { "id": 1, "name": "Alice" }, { "id": 2, "name": "Bob" } ] }
Then you have to take it like this:
for item in data['results']: print(item['name'])
If the data volume is large and the structure is complex, you can consider using pandas for further processing and converting the list into a DataFrame:
import pandas as pd df = pd.DataFrame(data['results'])
Basically that's it. The operation is not complicated, but details are easy to ignore, such as error handling, paging logic, and data extraction methods. Just practice a few more times and you should be able to master it.
The above is the detailed content of Accessing data from a web API in Python. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

The key to dealing with API authentication is to understand and use the authentication method correctly. 1. APIKey is the simplest authentication method, usually placed in the request header or URL parameters; 2. BasicAuth uses username and password for Base64 encoding transmission, which is suitable for internal systems; 3. OAuth2 needs to obtain the token first through client_id and client_secret, and then bring the BearerToken in the request header; 4. In order to deal with the token expiration, the token management class can be encapsulated and automatically refreshed the token; in short, selecting the appropriate method according to the document and safely storing the key information is the key.

In Python, the method of traversing tuples with for loops includes directly iterating over elements, getting indexes and elements at the same time, and processing nested tuples. 1. Use the for loop directly to access each element in sequence without managing the index; 2. Use enumerate() to get the index and value at the same time. The default index is 0, and the start parameter can also be specified; 3. Nested tuples can be unpacked in the loop, but it is necessary to ensure that the subtuple structure is consistent, otherwise an unpacking error will be raised; in addition, the tuple is immutable and the content cannot be modified in the loop. Unwanted values can be ignored by \_. It is recommended to check whether the tuple is empty before traversing to avoid errors.

Python implements asynchronous API calls with async/await with aiohttp. Use async to define coroutine functions and execute them through asyncio.run driver, for example: asyncdeffetch_data(): awaitasyncio.sleep(1); initiate asynchronous HTTP requests through aiohttp, and use asyncwith to create ClientSession and await response result; use asyncio.gather to package the task list; precautions include: avoiding blocking operations, not mixing synchronization code, and Jupyter needs to handle event loops specially. Master eventl

Pure functions in Python refer to functions that always return the same output with no side effects given the same input. Its characteristics include: 1. Determinism, that is, the same input always produces the same output; 2. No side effects, that is, no external variables, no input data, and no interaction with the outside world. For example, defadd(a,b):returna b is a pure function because no matter how many times add(2,3) is called, it always returns 5 without changing other content in the program. In contrast, functions that modify global variables or change input parameters are non-pure functions. The advantages of pure functions are: easier to test, more suitable for concurrent execution, cache results to improve performance, and can be well matched with functional programming tools such as map() and filter().

Yes,aPythonclasscanhavemultipleconstructorsthroughalternativetechniques.1.Usedefaultargumentsinthe__init__methodtoallowflexibleinitializationwithvaryingnumbersofparameters.2.Defineclassmethodsasalternativeconstructorsforclearerandscalableobjectcreati

ifelse is the infrastructure used in Python for conditional judgment, and different code blocks are executed through the authenticity of the condition. It supports the use of elif to add branches when multi-condition judgment, and indentation is the syntax key; if num=15, the program outputs "this number is greater than 10"; if the assignment logic is required, ternary operators such as status="adult"ifage>=18else"minor" can be used. 1. Ifelse selects the execution path according to the true or false conditions; 2. Elif can add multiple condition branches; 3. Indentation determines the code's ownership, errors will lead to exceptions; 4. The ternary operator is suitable for simple assignment scenarios.

In Python, although there is no built-in final keyword, it can simulate unsurpassable methods through name rewriting, runtime exceptions, decorators, etc. 1. Use double underscore prefix to trigger name rewriting, making it difficult for subclasses to overwrite methods; 2. judge the caller type in the method and throw an exception to prevent subclass redefinition; 3. Use a custom decorator to mark the method as final, and check it in combination with metaclass or class decorator; 4. The behavior can be encapsulated as property attributes to reduce the possibility of being modified. These methods provide varying degrees of protection, but none of them completely restrict the coverage behavior.

In Python, using a for loop with the range() function is a common way to control the number of loops. 1. Use when you know the number of loops or need to access elements by index; 2. Range(stop) from 0 to stop-1, range(start,stop) from start to stop-1, range(start,stop) adds step size; 3. Note that range does not contain the end value, and returns iterable objects instead of lists in Python 3; 4. You can convert to a list through list(range()), and use negative step size in reverse order.
