理解python中{:.2}的语法含义

Question

我正在为一个特定的数据集建立一个线性回归模型，我正在遵循我在你的管子上找到的一个例子，在某个时候，我计算出了峰度和偏斜度，如下所示：

# calculate the excess kurtosis using the fisher method. The alternative is Pearson which 
calculates regular kurtosis.
exxon_kurtosis = kurtosis(price_data['exxon_price'], fisher = True)
oil_kurtosis = kurtosis(price_data['oil_price'], fisher = True)

# calculate the skewness
exxon_skew = skew(price_data['exxon_price'])
oil_skew = skew(price_data['oil_price'])

display("Exxon Excess Kurtosis: {:.2}".format(exxon_kurtosis))  # this looks fine
display("Oil Excess Kurtosis: {:.2}".format(oil_kurtosis))      # this looks fine

display("Exxon Skew: {:.2}".format(exxon_skew))          # moderately skewed
display("Oil Skew: {:.2}".format(oil_skew))              # moderately skewed, it's a 
little high but we will accept it.

我是python的新手，下面的代码使我在这里感到困惑{：2}，请有人解释一下这一部分{：2}

display("Exxon Excess Kurtosis: {:.2}".format(exxon_kurtosis))

Answer 1

kurtosis和skew函数正在进行计算，而display函数可能只是该环境的某种形式的print()！

".. {:.2}".format(x)是一个字符串格式化程序，它将浮点数转换为2个有效数字。

>>> "{:.2}".format(3.0)
'3.0'
>>> "{:.2}".format(0.1555)
'0.16'
>>> "{:.2}".format(3.1555)
'3.2'

字符串格式是取之不尽的详见。