ApathyBear questions

• How setState with one value work?
• Django 1.8: ImproperlyConfigured: Module "django.contrib.auth.middleware" does not define a "SessionAuthenticationMiddleware" attribute/class
• Python requests, keep getting 401 error when accessing an API
• Python: Convert subtracted unix time into hours/mins/seconds
• Bootstrap 4 center-block unable to center
• Reactjs this.state giving Uncaught TypeError: Cannot read property 'groupsData' of null
• django models: Good way of storing a multiline line address as one model field
• Why does this lambda require *arg, what difference does it make?
• TypeError: this.props.data.map is not a function, but data is a list
• Django urls.py, what does the name parameter do?

ApathyBear answers