# ERROR: Invalid requirement: 'requests >=2.0 <3.0' (from line 4 of requirements.txt)
Hint: = is not a valid operator. Did you mean == ?

- **ID:** `python/pip-requirement-parse-error`
- **Domain:** python
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The requirement line has a malformed version specifier, often a single `=` instead of `==`, or a space between operators.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.8 | active | — | — |
| 3.9 | active | — | — |
| 3.10 | active | — | — |
| 3.11 | active | — | — |
| 3.12 | active | — | — |

## Workarounds

1. **** (98% success)
   ```
   Change `requests >=2.0 <3.0` to `requests>=2.0,<3.0`
   ```
2. **** (90% success)
   ```
   python -c "from packaging.requirements import Requirement; [Requirement(l.strip()) for l in open('requirements.txt') if l.strip() and not l.startswith('#')]"
   ```

## Dead Ends

- **** — requirements.txt is parsed by pip, not the shell; quoting does not change the grammar. (90% fail)
- **** — The parser is strict by design; upgrading does not accept invalid syntax. (85% fail)
- **** — The error occurs during parsing, before resolution. (95% fail)