Question

我编写了以下代码来存储数据，检索值并将数据存储到对象中

// The _to and _from fields become account entries
8441142 { Accounts: '0xda7C4aAb9bb74710498485ed01CB4D521f7b4456',
                    '0x24fa98CA3aB52D8CF562B641AbC4b12861e991Cf'}
// Add accounts that did not previously exist, ignore ones already in here
8441157 { Accounts: 0xda7C4aAb9bb74710498485ed01CB4D521f7b4456',
                  '0x24fa98CA3aB52D8CF562B641AbC4b12861e991Cf', '0x46340b20830761efd32832A74d7169B29FEB9758','0xeE7D76D5B00A10B49e37a9e26a7678be1EE607F4'}
// Add accounts that did not previously exist, ignore ones already in here
8441167 { Accounts: '0x2baa435Ca4B9dE4a135cAE11f4c04C4a1d334089','0x9fa7f05C9AaE89752fa9273CFAcADF602657599d'}

这很好用，它的输出是：

df = pd.DataFrame({
  "col2": ['GE1', 'GE1', 'GE1', 'GE2', 'GE2'],
  "col3": [np.nan, '1.2', np.nan, '1.3', np.nan]
})

unique_values = df.groupby("col2").first()
final_df = df.join(unique_values, on="col2", lsuffix="_orig")

我想将其转换为format，其中每个帐户（_to和_from）并作为帐户添加到块上方的索引中，即

--porcelain

我希望能找到一些有关如何有效完成此操作的指示。

Answer 1

在循环外使用变量来保存上一个块中的帐户列表。复制它，然后将新帐户推送到它。

  let last_accounts = [];
  for (const [key, {blockNumber, returnValues: {_from, _to}}] of Object.entries(obj)) {
    let these_accounts = last_accounts.slice(); // copy accounts from previous block
    if (!these_accounts.includes(_from)) {
        these_accounts.push(_from);
    }
    if (!these_accounts.includes(_to)) {
        these_accounts.push(_to);
    }
    accounts[blockNumber] = {Accounts: these_accounts};
    last_accounts = these_accounts;
  }

仅当值不存在时才向对象添加新的数组条目

1 个答案: