Repository: pandas-dev/pandas

Issue:
requirements-dev.txt: "Could not find a version that satisfies the requirement pyqt"
I followed the contributors guide and set up the dev environment without anaconda. Generally works, except for a small problem in

```
python -m pip install -r requirements-dev.txt
```
which fails with
```
Could not find a version that satisfies the requirement pyqt
```

`pyqt` is not known on PyPI and I resolved the problem by replacing it with `pyqt5`, i.e. with the following patch:

```
From a284ac89a43237784d663b2a475eead953e8a64d Mon Sep 17 00:00:00 2001
From: Jan-Philip Gehrcke <jgehrcke@googlemail.com>
Date: Wed, 12 Jun 2019 20:04:06 +0200
Subject: [PATCH] BUG: requirements-dev: Could not find ... pyqt

As of today 'pyqt' is not a valid PyPI project.

This results in the error message

    Could not find a version that satisfies the requirement pyqt

when running

    python -m pip install -r requirements-dev.txt

from the contributors guide.
---
 requirements-dev.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/requirements-dev.txt b/requirements-dev.txt
index 46e857f2e9e..73b591ce8f6 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -44,7 +44,7 @@ html5lib
 lxml
 openpyxl
 pyarrow>=0.9.0
-pyqt
+pyqt5
 tables>=3.4.2
 python-snappy
 s3fs
@@ -52,4 +52,4 @@ sqlalchemy
 xarray
 xlrd
 xlsxwriter
-xlwt
\ No newline at end of file
+xlwt
```

But that does not pass CI because of
```
requirements-dev.txt(,): error : `requirements-dev.txt` has to be generated with `ci/../scripts/generate_pip_deps_from_conda.py` after `environment.yml` is modified.
```

From here I am "giving up" but I would at least like to leave this report.


Discussion:
(seen in https://github.com/pandas-dev/pandas/pull/26818).
@jgehrcke : We can either put pyqt5 package in the requirement.txt but it's supported only in python3 .
as stated here https://github.com/pypa/pip/issues/5014 ,pyqt for python2 needs to compiled manually.
what are your suggestions?
We're python3 only now.
What's bringing in the qt dependency? The clipboard tests?
yup and in this commit https://github.com/jgehrcke/pandas/commit/c3b5a24607754c34d2f1d4d61e2a485f51eb3c22 pyqt5 is misspelled and maybe they rolledback due to that reason. 
it can be added as PyQt5 in the list and then it works
>  in this commit jgehrcke@c3b5a24 pyqt5 is misspelled and maybe they rolledback due to that reason.


@dhirensr in my patch shown in _this_ issues description (first comment above) you can see:
```
-pyqt
+pyqt5
```
What's misspelled here? Mhm. 

As I wrote above this breaks the pandas CI with

```
requirements-dev.txt(,): error : `requirements-dev.txt` has to be generated with `ci/../scripts/generate_pip_deps_from_conda.py` after `environment.yml` is modified.
```
which, I suppose, can be fixed easily -- it just wasn't my priority, and instead I opened this issue here.

@jgehrcke : i mean it should be PyQt5 and not pyqt5 anyways.Note p and q are capital
if it's not a priority we can label it as not-priority so that many people don't come here and work on it.
capitalization shouldn't matter for pip. pip will normalize them.

The TODO for this issue is to

1. Find out what the PyPI package name for Conda's pyqt is (probably https://pypi.org/project/PyQt5/)
2. update `generate_pip_deps_from_conda.py` to map `pyqt` to `pyqt5`. See `pytables` / `tables`.

Resolving patch:
diff --git a/scripts/generate_pip_deps_from_conda.py b/scripts/generate_pip_deps_from_conda.py
--- a/scripts/generate_pip_deps_from_conda.py
+++ b/scripts/generate_pip_deps_from_conda.py
@@ -20,7 +20,7 @@
 
 
 EXCLUDE = {"python=3"}
-RENAME = {"pytables": "tables"}
+RENAME = {"pytables": "tables", "pyqt": "pyqt5"}
 
 
 def conda_package_to_pip(package):


Test patch: