我是docker的新手，正在尝试学习它。我正在关注本教程：https : //docs.docker.com/get-
started/part2/#apppy

所以我在Windows上安装了Docker。创建了3个文件，app.py，Dockefile和requirements.txt

我的docker文件看起来像这样

# Use an official Python runtime as a parent image
FROM python:2.7-slim

# Set the working directory to /app
WORKDIR /app

# Copy the current directory contents into the container at /app
ADD . /app

# Install any needed packages specified in requirements.txt
RUN pip install --trusted-host pypi.python.org -r requirements.txt

# Make port 80 available to the world outside this container
EXPOSE 80

# Define environment variable
ENV NAME World
CMD ["python", "app.py"]

当我在Powershell中运行它时

docker build -t friendlybuild .

但是结果是：

Error response from daemon: Dockerfile parse error line 1: unknown instruction: #

就像它不起作用

我不知道为什么它不起作用