Python 将值存储在元组而不是字典中

目前，我正在使用以下脚本从10.000多个数据库获取数据：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    identity, closing_date, owner_identity = cursor.fetchall()
    return {
        "identity": identity,
        "closing_date": closing_date,
        "owner_identity": owner_identity
    }

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

CompanyData = collections.namedtuple('CompanyData', 'identity, closing_date, owner_identity')

data = CompanyData(cursor.fetchone())
return data

for company in options["databases"]["data"]:
    do_something_with(company.identity, company.owner_identity)

然后我反复浏览字典列表：

for data in options["databases"]["data"]:
    # i do something here with identity, closing_date and owner_identity

我正在考虑更改脚本以返回元组，而不是字典：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    return cursor.fetchall()

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

然后我可以：

for identity, closing_date, owner_identity in options["databases"]["data"]:
    # I do something here with identity, closing_date and owner_identity

这会更快（有时我会有20000本字典），但没有解释就无法阅读。这被认为是一种不好的做法吗？我应该避免吗？我看到Python程序员喜欢列表和元组，但我还不知道他们是否也使用元组来存储数据。

考虑在

get\u data

函数中使用

您可以这样声明一个：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    identity, closing_date, owner_identity = cursor.fetchall()
    return {
        "identity": identity,
        "closing_date": closing_date,
        "owner_identity": owner_identity
    }

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

CompanyData = collections.namedtuple('CompanyData', 'identity, closing_date, owner_identity')

data = CompanyData(cursor.fetchone())
return data

for company in options["databases"]["data"]:
    do_something_with(company.identity, company.owner_identity)

然后，您可以创建一个如下所示的：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    identity, closing_date, owner_identity = cursor.fetchall()
    return {
        "identity": identity,
        "closing_date": closing_date,
        "owner_identity": owner_identity
    }

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

CompanyData = collections.namedtuple('CompanyData', 'identity, closing_date, owner_identity')

data = CompanyData(cursor.fetchone())
return data

for company in options["databases"]["data"]:
    do_something_with(company.identity, company.owner_identity)

然后像这样访问它：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    identity, closing_date, owner_identity = cursor.fetchall()
    return {
        "identity": identity,
        "closing_date": closing_date,
        "owner_identity": owner_identity
    }

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

CompanyData = collections.namedtuple('CompanyData', 'identity, closing_date, owner_identity')

data = CompanyData(cursor.fetchone())
return data

for company in options["databases"]["data"]:
    do_something_with(company.identity, company.owner_identity)

考虑在

get_data

函数中使用

您可以这样声明一个：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    identity, closing_date, owner_identity = cursor.fetchall()
    return {
        "identity": identity,
        "closing_date": closing_date,
        "owner_identity": owner_identity
    }

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

CompanyData = collections.namedtuple('CompanyData', 'identity, closing_date, owner_identity')

data = CompanyData(cursor.fetchone())
return data

for company in options["databases"]["data"]:
    do_something_with(company.identity, company.owner_identity)

然后，您可以创建一个如下所示的：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    identity, closing_date, owner_identity = cursor.fetchall()
    return {
        "identity": identity,
        "closing_date": closing_date,
        "owner_identity": owner_identity
    }

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

CompanyData = collections.namedtuple('CompanyData', 'identity, closing_date, owner_identity')

data = CompanyData(cursor.fetchone())
return data

for company in options["databases"]["data"]:
    do_something_with(company.identity, company.owner_identity)

然后像这样访问它：

def get_data(cursor):
    cursor.execute("SELECT * FROM COMPANIES")
    identity, closing_date, owner_identity = cursor.fetchall()
    return {
        "identity": identity,
        "closing_date": closing_date,
        "owner_identity": owner_identity
    }

def collect_databases_data(options):
    options["databases"]["data"] = [
        get_data(connection.cursor())
        for connection in options["databases"].values()
    ]
    return options

CompanyData = collections.namedtuple('CompanyData', 'identity, closing_date, owner_identity')

data = CompanyData(cursor.fetchone())
return data

for company in options["databases"]["data"]:
    do_something_with(company.identity, company.owner_identity)

---

您是否尝试过使用NamedTuple来表示行？这应该比字典更轻，但仍嵌入描述。您是否尝试使用NamedTuple表示行？这应该比一本字典更轻，但仍然嵌入了描述。