python - 在 Python 中的 For 语句中为输入字段循环一个变量

Question

我想向用户显示另一个输入字段，但它不起作用，除非我在 new_url 的 For 循环中执行此操作 new_url = input("Please enter new URL for a screenshot (按返回停止):").strip() 但我想将输入字段移动到 For 循环之外的某个地方，所以我尝试对输入字段执行此操作，例如 new_url = new_url_input 并获取 new_url_input 变量并将其添加到我的代码中的其他位置，例如 new_url_input = input("Please enter new URL for a screenshot (press return to stop): ").strip( ) 但是当我这样做时，它只显示一次代码，但它应该像用户按下输入时那样工作，它显示另一个输入字段。请看这个question/answer有关我的主题的更多信息。

原始代码:

# Load the data
file_name = file_name = path/to/json/file
with open(file_name) as fh:
    full_data = json.load(fh)

# Dig into the data to find the screenshots
screen_shots = full_data['tabs'][0]['views'][1]['screenshots']

# Loop over each screen shot, updating each one
for number, screen_shot in enumerate(screen_shots):
    new_url = input("Please enter new URL (press return to stop): ").strip()

    if new_url:
        screen_shot.update({"url": new_url, "fullSizeURL": new_url})
    else:
        break

# Remove all entries which we did not update
screen_shots = screen_shots[:number]

# Save the data
with open(file_name, 'w') as fh:
    json.dump(full_data, fh, indent=4)

我希望它如何工作/看起来的示例:

new_url_input = input("Please enter new URL (press return to stop): ").strip()

# Load the data
file_name = path/to/json/file
with open(file_name) as fh:
    full_data = json.load(fh)

# Dig into the data to find the screenshots
screen_shots = full_data['tabs'][0]['views'][1]['screenshots']

# Loop over each screen shot, updating each one
for number, screen_shot in enumerate(screen_shots):
    new_url = new_url_input

    if new_url:
        screen_shot.update({"url": new_url, "fullSizeURL": new_url})
    else:
        break

 # Remove all entries which we did not update
 screen_shots = screen_shots[:number]

 # Save the data
 with open(file_name, 'w') as fh:
     json.dump(full_data, fh, indent=4)

Answer 1

当您调用 input() 时，它返回一个字符串，在循环中您只是将该字符串分配给一个新变量。您需要以某种方式再次调用 input() ，即使它是将其包装在一个函数中，例如使用 lambda 如下...

new_url_input = lambda: input("Please enter new URL (press return to stop): ").strip()

# ...other code...

for number, screen_shot in enumerate(screen_shots):
    new_url = new_url_input()

---

编辑:现在我明白你在说什么(输入提示符上的说明有帮助)，我认为这就是你想要做的......

new_url_inputs = []
input_prompt = 'Please enter new URL (press return to stop): '
new_url_input = input(input_prompt).strip()
while new_url_input:
    new_url_inputs.append(new_url_input)
    new_url_input = input(input_prompt).strip()

# ...other code...

for number, screen_short in enumerate(screen_shots):
    new_url = new_url_inputs[number]
    # ...etc...