Python 3.x psycopg2.DataError:双精度类型的输入语法无效：“0”；空"；

我正试图使用copy-from命令和Python-psycopg2库上传一个CSV文件。我知道错误源于试图将char值插入双精度列，但在创建csv文件时，我将null值指定为

“null”

，并且在Postgres copy命令中，我还将null指定为

“null”

，因此我不确定上传时为什么不转换这些值

创建csv文件：

with file_path.open(mode='w', newline='') as outfile:
    csv_writer = csv.writer(outfile, delimiter=delimiter, quoting=csv.QUOTE_NONNUMERIC)

    if include_headers:
        csv_writer.writerow(col[0] for col in self.cursor.description)
    for row in self.cursor:
        csv_writer.writerow(['NULL' if value is None else value for value in row])

sql = """COPY {table} FROM STDIN WITH (DELIMITER '{sep}', NULL 'NULL', FORMAT CSV, HEADER True);""".format(table=table, sep=sep)

with open(file) as f:
    self.cursor.copy_expert(sql=sql, file=f, size=size)
self.commit()

psycopg2.DataError: invalid input syntax for type double precision:
"NULL" CONTEXT:  COPY test_table, line 25, column Lat:
"NULL"

将文件上载到postgres:

with file_path.open(mode='w', newline='') as outfile:
    csv_writer = csv.writer(outfile, delimiter=delimiter, quoting=csv.QUOTE_NONNUMERIC)

    if include_headers:
        csv_writer.writerow(col[0] for col in self.cursor.description)
    for row in self.cursor:
        csv_writer.writerow(['NULL' if value is None else value for value in row])

sql = """COPY {table} FROM STDIN WITH (DELIMITER '{sep}', NULL 'NULL', FORMAT CSV, HEADER True);""".format(table=table, sep=sep)

with open(file) as f:
    self.cursor.copy_expert(sql=sql, file=f, size=size)
self.commit()

psycopg2.DataError: invalid input syntax for type double precision:
"NULL" CONTEXT:  COPY test_table, line 25, column Lat:
"NULL"

错误：

with file_path.open(mode='w', newline='') as outfile:
    csv_writer = csv.writer(outfile, delimiter=delimiter, quoting=csv.QUOTE_NONNUMERIC)

    if include_headers:
        csv_writer.writerow(col[0] for col in self.cursor.description)
    for row in self.cursor:
        csv_writer.writerow(['NULL' if value is None else value for value in row])

sql = """COPY {table} FROM STDIN WITH (DELIMITER '{sep}', NULL 'NULL', FORMAT CSV, HEADER True);""".format(table=table, sep=sep)

with open(file) as f:
    self.cursor.copy_expert(sql=sql, file=f, size=size)
self.commit()

psycopg2.DataError: invalid input syntax for type double precision:
"NULL" CONTEXT:  COPY test_table, line 25, column Lat:
"NULL"

---

您应该使用

QUOTE\u MINIMAL

，否则您的

None

将在文件中显示为

“NULL”

（包括引号），这就是

COPY

无法正确识别它们的原因

---

但我认为您不必经历所有这些，因为

COPY

能够很好地处理CSV文件。打开文件并使用

copy_from

和

copy_to

方法。

您知道从sql查询创建csv文件的更好方法吗？必须迭代所有的值来转换空值，这样才能使用copy命令，这似乎效率低下。