Reading JSON files can be implemented in Python through the json module. The specific steps are: use the open() function to open the file, use json.load() to load the content, and the data will be returned in a dictionary or list form; if you process JSON strings, you should use json.loads(). Common problems include file path errors, incorrect JSON format, encoding problems and data type conversion differences. Pay attention to path accuracy, format legality, encoding settings, and mapping of boolean values and null.

The role of Ethereum smart contract is to realize decentralized, automated and transparent protocol execution. Its core functions include: 1. As the core logic layer of DApp, it supports token issuance, DeFi, NFT and other functions; 2. Automatically execute contracts through code to reduce the risks of human intervention and fraud; 3. Build a DeFi ecosystem so that users can directly conduct financial operations such as lending and transactions; 4. Create and manage digital assets to ensure uniqueness and verifiability; 5. Improve the transparency and security of supply chain and identity verification; 6. Support DAO governance and realize decentralized decision-making.

To identify fake altcoins, you need to start from six aspects. 1. Check and verify the background of the materials and project, including white papers, official websites, code open source addresses and team transparency; 2. Observe the online platform and give priority to mainstream exchanges; 3. Beware of high returns and people-pulling modes to avoid fund traps; 4. Analyze the contract code and token mechanism to check whether there are malicious functions; 5. Review community and media operations to identify false popularity; 6. Follow practical anti-fraud suggestions, such as not believing in recommendations or using professional wallets. The above steps can effectively avoid scams and protect asset security.

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.

The shutdown command of Linux/macOS can be shut down, restarted, and timed operations through parameters. 1. Turn off the machine immediately and use sudoshutdownnow or -h/-P parameters; 2. Use the time or specific time point for the shutdown, cancel the use of -c; 3. Use the -r parameters to restart, support timed restart; 4. Pay attention to the need for sudo permissions, be cautious in remote operation, and avoid data loss.

DAI is suitable for users who attach importance to the concept of decentralization, actively participate in the DeFi ecosystem, need cross-chain asset liquidity, and pursue asset transparency and autonomy. 1. Supporters of the decentralization concept trust smart contracts and community governance; 2. DeFi users can be used for lending, pledge, and liquidity mining; 3. Cross-chain users can achieve flexible transfer of multi-chain assets; 4. Governance participants can influence system decisions through voting. Its main scenarios include decentralized lending, asset hedging, liquidity mining, cross-border payments and community governance. At the same time, it is necessary to pay attention to system risks, mortgage fluctuations risks and technical threshold issues.

Ordinary investors can discover potential tokens by tracking "smart money", which are high-profit addresses, and paying attention to their trends can provide leading indicators. 1. Use tools such as Nansen and Arkham Intelligence to analyze the data on the chain to view the buying and holdings of smart money; 2. Use Dune Analytics to obtain community-created dashboards to monitor the flow of funds; 3. Follow platforms such as Lookonchain to obtain real-time intelligence. Recently, Cangming Money is planning to re-polize LRT track, DePIN project, modular ecosystem and RWA protocol. For example, a certain LRT protocol has obtained a large amount of early deposits, a certain DePIN project has been accumulated continuously, a certain game public chain has been supported by the industry treasury, and a certain RWA protocol has attracted institutions to enter.

Is DAI suitable for long-term holding? The answer depends on individual needs and risk preferences. 1. DAI is a decentralized stablecoin, generated by excessive collateral for crypto assets, suitable for users who pursue censorship resistance and transparency; 2. Its stability is slightly inferior to USDC, and may experience slight deansal due to collateral fluctuations; 3. Applicable to lending, pledge and governance scenarios in the DeFi ecosystem; 4. Pay attention to the upgrade and governance risks of MakerDAO system. If you pursue high stability and compliance guarantees, it is recommended to choose USDC; if you attach importance to the concept of decentralization and actively participate in DeFi applications, DAI has long-term value. The combination of the two can also improve the security and flexibility of asset allocation.