有没有办法将数据帧打印到列对齐的日志文件中

Question

我正试图将数据帧打印到日志文件中，但列未对齐。我提出了这个解决方案，将数据帧列和行作为列表，然后将列和浮点数据转换为字符串，但必须有更好的方法。

logging.error(f'Quality Metrics for Reconstructed File are Lower than Reference!!!')
print(df.shape)
columns = df_res.columns
msg = ' '.join(columns)
print(msg)
logging.error(msg)
data = df_res.iloc[0,:].tolist()
msg = '   '.join(map(str, data))
print(msg)
logging.error(msg)```
This is what the log file looks like.
2022-08-24 16:03:49,084 [ERROR] mse_avg mse_r mse_g mse_b psnr_avg psnr_r psnr_g psnr_b
2022-08-24 16:03:51,263 [ERROR] 0.02   0.01   0.03   0.01   65.44   67.82   62.78   67.82
You can see that the columns are not aligned correctly. Any advice on a better way to do this so that my log output is properly formatted?

Answer 1

此示例使用str.format正确格式化列标题和数据帧第一行的值：

max_column_len = len(max(df.columns, key=len))
fmt = "{{:>{}}}  ".format(max_column_len) * len(df.columns)
columns = fmt.format(*df.columns)
first_row = fmt.format(*df.iloc[0])
print(columns)    # <--- you can use `columns` in your logging function
print(first_row)  # <--- ...

---

打印：

mse_avg     mse_r     mse_g     mse_b  psnr_avg    psnr_r    psnr_g    psnr_b  
0.02      0.01      0.03      0.01     65.44     67.82     62.78     67.82  

---

使用的数据帧：

mse_avg  mse_r  mse_g  mse_b  psnr_avg  psnr_r  psnr_g  psnr_b
0     0.02   0.01   0.03   0.01     65.44   67.82   62.78   67.82

---

另一种解决方案：

# convert dataframe string and then split it:
for line in str(df).splitlines():
print(line)

Answer 2

您可以使用以下panda方法：

string = df.to_csv(sep='t')

它将用制表器将条目分隔开，制表器在大多数文本编辑器中应该对齐显示。