ValueError: 类型“str”的对象的格式代码“e”未知

Question

How to solve this error I am trying to get the number of coins for usdt For example the number of the quantity I want to buy against the usdt: 17.493796277071922

 def format_value(valuetoformatx,fractionfactorx):
    value = valuetoformatx
    fractionfactor = fractionfactorx
    Precision = abs(int(f'{fractionfactor:e}'.split('e')[-1]))
    FormattedValue = float('{:0.0{}f}'.format(value, Precision))
    return FormattedValue       
 def pairPriceinfo(ticker,client): 
    info = client.get_symbol_info(ticker)
    minPrice = pd.to_numeric(info['filters'][0]['minPrice'])  
    return minPrice
def pairQtyinfo(ticker,client):
    info = client.get_symbol_info(ticker)
    minQty = pd.to_numeric(info['filters'][2]['minQty'])   
    return minQty 

*error*
Precision= abs(int(f'{fractionfactor:e}'.split('e')[-1]))
ValueError: Unknown format code 'e' for object of type 'str'

*Please do not close the question

Answer 1

The error message tells you exactly what's wrong. I suggest learning how to read Python's error messages, as oftentimes they are sufficient for debugging.

In [1]: f"{'1634':e}"
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-1-b8ad0a2d3495> in <module>
----> 1 f"{'1634':e}"

ValueError: Unknown format code 'e' for object of type 'str'

In [2]: f"{1634:e}"
Out[2]: '1.634000e+03'

The problem is caused by fractionfactor being a string, and not a number, as described by the ValueError message:

Unknown format code 'e' for object of type 'str'

Strings are not numbers, so it doesn't make any sense to ask Python to display a string in scientific notation.