问如何强制bigquery在没有模式和autodetect=False的情况下将csv文件作为字符串加载

EN

def getschema(file_path):
'''Get schema from CSV with all columns as string'''
schema = []
with open(file_path, 'r') as read_obj:
    # pass the file object to DictReader() to get the DictReader object
    csv_dict_reader = DictReader(read_obj)
    # get column names from a csv file
    column_names = csv_dict_reader.fieldnames
for c in column_names:
    schema.append(bigquery.SchemaField(c,"STRING"))
return schema