python - python: pip 无法安装 matplotlib v.3.1.1

Question

% pip -r requirements.txt

其中 requirements.txt 有以下行：

matplotlib==3.1.1

命令失败：

ERROR: Could not find a version that satisfies the requirement matplotlib==3.1.1 (from -r requirements.txt (line 9)) (from versions: 0.86, 0.86.1, 0.86.2, 0.91.0, 0.91.1, 1.0.1, 1.1.0, 1.1.1, 1.2.0, 1.2.1, 1.3.0, 1.3.1, 1.4.0, 1.4.1rc1, 1.4.1, 1.4.2, 1.4.3, 1.5.0, 1.5.1, 1.5.2, 1.5.3, 2.0.0b1, 2.0.0b2, 2.0.0b3, 2.0.0b4, 2.0.0rc1, 2.0.0rc2, 2.0.0, 2.0.1, 2.0.2, 2.1.0rc1, 2.1.0, 2.1.1, 2.1.2, 2.2.0rc1, 2.2.0, 2.2.2, 2.2.3, 2.2.4, 2.2.5, 3.0.0rc2, 3.0.0, 3.0.1, 3.0.2, 3.0.3)
ERROR: No matching distribution found for matplotlib==3.1.1 (from -r requirements.txt (line 9))

我都试过了pip install -r requirements.txt，pip3 install -r requirements.txt没有区别。

虽然pip search matplotlib确实表明“matplotlib (3.1.3)”是可用的。我究竟做错了什么？

标签： pythonmatplotlibpip