python - 将json dict转换为pandas df中的行

Question

我已经从 url 中提取了 JSON 数据。结果是一本字典。我如何转换这个字典，使每个键都是一列，时间戳是每行的索引 - 每次调用 url 时，dict values 对应于行条目？

数据如下:

with urllib.request.urlopen('https://api.blockchain.info/stats') as url:
    block_data = json.loads(url.read().decode())

# Convert to Pandas
block_df = pd.DataFrame(block_data)

我试过:

block_df = pd.DataFrame(block_data)
block_df = pd.DataFrame(block_data, index = 'timestamp')
block_df = pd.DataFrame.from_dict(block_data)
block_df = pd.DataFrame.from_dict(block_data, orient = 'columns')

但是所有的尝试都会给出不同的错误:

ValueError: If using all scalar values, you must pass an index

和

TypeError: Index(...) must be called with a collection of some kind, 'timestamp' was passed

Answer 1

用列表包装block_data

pd.DataFrame([block_data]).set_index('timestamp')

               blocks_size    difficulty  estimated_btc_sent  estimated_transaction_volume_usd     hash_rate  market_price_usd  miners_revenue_btc  miners_revenue_usd  minutes_between_blocks  n_blocks_mined  n_blocks_total   n_btc_mined    n_tx  nextretarget   total_btc_sent  total_fees_btc           totalbc  trade_volume_btc  trade_volume_usd
timestamp                                                                                                                                                                                                                                                                                                                                                
1504121943000    167692649  888171856257      24674767461479                      1.130867e+09  7.505715e+09           4583.09                2540         11645247.85                    7.92             170          482689  212500000000  281222        483839  174598204968248     41591624963  1653361250000000          43508.93      1.994054e+08

---

用datetime索引。

df = pd.DataFrame([block_data]).set_index('timestamp')
df.index = pd.to_datetime(df.index, unit='ms')
df

                     blocks_size    difficulty  estimated_btc_sent  estimated_transaction_volume_usd     hash_rate  market_price_usd  miners_revenue_btc  miners_revenue_usd  minutes_between_blocks  n_blocks_mined  n_blocks_total   n_btc_mined    n_tx  nextretarget   total_btc_sent  total_fees_btc           totalbc  trade_volume_btc  trade_volume_usd
timestamp                                                                                                                                                                                                                                                                                                                                                      
2017-08-30 19:39:03    167692649  888171856257      24674767461479                      1.130867e+09  7.505715e+09           4583.09                2540         11645247.85                    7.92             170          482689  212500000000  281222        483839  174598204968248     41591624963  1653361250000000          43508.93      1.994054e+08