NameError: name 'writer' is not defined

Question

def create_and_update_worksheets():
    """
    Add 'Player statistics' if the worksheet is not in file_name. 
    Otherwise, it will update the worksheet itself.
    """

    os.chdir(os.path.dirname(os.path.abspath(__file__)))

    writer = pd.ExcelWriter(file_name, engine='openpyxl')
    row = 0

    for item in worksheets['Game Schedule'].values():
        multiple_dfs(item, 'Game Schedule')

    for sheet in writer.sheets.values():
        resize_columns(sheet)

    writer.save()
    writer.close()

在此实际代码中，writer 和 row 已经定义，但如果我决定将 multiple_dfs 实现为：

，我会遇到一些错误

def multiple_dfs(item, sheets):
    """
    Put multiple dataframes into one xlsx sheet
    """

    response = send_request(item).content
    df = pd.read_csv(io.StringIO(response.decode('utf-8')))

    df.to_excel(writer, sheets, startrow=row, index=False)
    row = row + len(df) + 2

我收到 writer 的以下错误，但 row 也发生了同样的事情。

Traceback (most recent call last):
  File "create_and_update_xlsx_sheets.py", line 66, in <module>
    create_and_update_worksheets()
  File "create_and_update_xlsx_sheets.py", line 56, in create_and_update_worksheets
    multiple_dfs(item, 'Game Schedule')
  File "create_and_update_xlsx_sheets.py", line 33, in multiple_dfs
    df.to_excel(writer, sheets, startrow=row, index=False)
NameError: name 'writer' is not defined

我该如何解决这些错误？我不想在 multiple_dfs 中重新定义它们，但我也需要在以后的函数中重新定义它们。

Answer 1

即使您从 writer 存在的作用域中调用函数，被调用者也看不到它，这就是 python 的作用域规则的工作方式。

我建议让您的 multiple_dfs 函数接受另一个名为 writer 的参数，该参数是您从调用函数传递过来的。如果除了 writer 之外还有多个参数要传递，则需要使用可变参数。

def multiple_dfs(item, sheets, *args):
    for i, var in enumerate(args, 1):
        print('variable {}: {}'.format(i, var))
    ...

呼叫 multiple_dfs:

multiple_dfs(item, 'Game Schedule', variable1, variable2, ...)

NameError: name 'writer' is not defined

NameError: name 'writer' is not defined

python

function

local-variables

parameter-passing

nameerror