pip install -r：仅安装新软件包

Question

Let's say my requirements.txt file is:

diff-match-patch==20121119
django-braces==1.4.0
django-crispy-forms==1.4.0

I install all the software with the following command:

pip install -r requirements.txt

Now let's say I add two packages:

diff-match-patch==20121119
django-braces==1.4.0
django-crispy-forms==1.4.0
django-custom-user==0.4
django-import-export==0.2.3

If I want to install the new packages only, that is, only the last two ones, what command should I use? If I run again the command pip install -r requirements.txt , it's going to download and try to install everything, including the packages already installed!

Answer 1

If you're worried about only upgrading certain packages, you can upgrade packages manually with pip install -U <package> .

If your concern is not freshly installing all of your dependencies every time, don't worry. If you run pip install -r requirements.txt without the -U (or --upgrade ) flag, it won't try to update previously installed packages, as mentioned in this answer .