在多行语句之间插入注释（带有行继续） [英] Put comments in between multi-line statement (with line continuation)

问题描述

当我编写以下pyspark命令时：

When i write a following pyspark command:

# comment 1
df = df.withColumn('explosion', explode(col('col1'))).filter(col('explosion')['sub_col1'] == 'some_string') \
    # comment 2
    .withColumn('sub_col2', from_unixtime(col('explosion')['sub_col2'])) \
    # comment 3
    .withColumn('sub_col3', from_unixtime(col('explosion')['sub_col3']))

我收到以下错误：

.withColumn('sub_col2', from_unixtime(col('explosion')['sub_col2']))
^
IndentationError: unexpected indent

是否可以在pyspark的多行命令行之间编写注释？

Is there a way to write comments in between the lines of multiple-line commands in pyspark?

推荐答案

这不是 pyspark 的问题，而是违反python语法的。

This is not a pyspark issue, but rather a violation of python syntax.

请考虑以下示例：

a, b, c = range(3)
a +\
# add b
b +\
# add c
c

结果是：

    a +# add b
              ^
SyntaxError: invalid syntax

\ 是连续字符，python将下一行中的所有内容解释为紧随其后发生的错误，

The \ is a continuation character and python interprets anything on the next line as occurring immediately after, causing your error.

一种解决方法是改用括号：

One way around this is to use parentheses instead:

(a +
# add b
b +
# add c
c)

分配给变量时，这看起来像是

When assigning to a variable this would look like

# do a sum of 3 numbers
addition = (a +
            # add b
            b +
            # add c
            c)

或者在您的情况下：

# comment 1
df = (df.withColumn('explosion', explode(col('col1')))
    .filter(col('explosion')['sub_col1'] == 'some_string')
    # comment 2
    .withColumn('sub_col2', from_unixtime(col('explosion')['sub_col2']))
    # comment 3
    .withColumn('sub_col3', from_unixtime(col('explosion')['sub_col3'])))

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