在进行字符串格式化时,字段名称中出现意外的"{"

Question

我正在尝试编写一个小脚本,它将自动化我需要编写的一些PHP样板.它应该将字符串的副本写入code输出文件,并为fields列表中的每个字典填写各种替换字段.

但是,我收到错误:

Traceback (most recent call last):
    File "writefields.py", line 43, in <module>
        formatted = code.format(**field)
ValueError: unexpected '{' in field name

据我所知,替换领域或应该导致问题的决定没有额外的括号,所以任何帮助将不胜感激.

code = '''
// {label}
add_filter( 'submit_job_form_fields', 'frontend_add_{fieldname}_field' );
function frontend_add_{fieldname}_field($fields) {
    $fields['job']['job_{fieldname}'] = array(
        'label' => __('{label}', 'job_manager'),
        'type' => 'text',
        'required' => {required},
        'priority' => 7,
        'placeholder' => '{placeholder}'
    );
    return $fields;
}
add_filter( 'job_manager_job_listing_data_fields', 'admin_add_{fieldname}_field' );
function admin_add_{fieldname}_field( $fields ) {
  $fields['_job_{fieldname}'] = array(
    'label'       => __( '{label}', 'job_manager' ),
    'type'        => 'text',
    'placeholder' => '{placeholder}',
    'description' => ''
  );
  return $fields;
}
'''

fields = [
    {
        'fieldname': 'salary',
        'label': 'Salary ($)',
        'required': 'true',
        'placeholder': 'e.g. 20000',
    },
    {
        'fieldname': 'test',
        'label': 'Test Field',
        'required': 'true',
        'placeholder': '',
    }
]

with open('field-out.txt', 'w') as f:
    for field in fields:
        formatted = code.format(**field)
        f.write(formatted)
        f.write('\n')

Answer 1

您需要将任何或不属于格式化占位符的内容加倍.例如,你有:{}

function admin_add_{fieldname}_field( $fields ) {
    [....]
}

在字符串中.在{和}有没有一个占位符的一部分.

加倍那些花括号逃脱了他们; 最终输出将再次包含单个{和}字符:

code = '''
// {label}
add_filter( 'submit_job_form_fields', 'frontend_add_{fieldname}_field' );
function frontend_add_{fieldname}_field($fields) {{
    $fields['job']['job_{fieldname}'] = array(
        'label' => __('{label}', 'job_manager'),
        'type' => 'text',
        'required' => {required},
        'priority' => 7,
        'placeholder' => '{placeholder}'
    );
    return $fields;
}}
add_filter( 'job_manager_job_listing_data_fields', 'admin_add_{fieldname}_field' );
function admin_add_{fieldname}_field( $fields ) {{
  $fields['_job_{fieldname}'] = array(
    'label'       => __( '{label}', 'job_manager' ),
    'type'        => 'text',
    'placeholder' => '{placeholder}',
    'description' => ''
  );
  return $fields;
}}
'''