23. Common pandas Mistakes and Fixes
Chala mitrano, pandas shyamchi library nahi — warnings ani silent NaNs daily yetat. Aaj aapan SettingWithCopy, dtypes, merge explosion, IST traps, filter bugs, debugging checklist. Ghabru naka; checklist vapruja.
What you will learn in this chapter
- SettingWithCopy / chained assignment
- Wrong dtypes and silent NaNs
- Merge row explosion (many-to-many)
- Timezone-naive vs IST mistakes
- Filters that drop too much / bad boolean ops
- A debugging checklist (
shape,isna,indicator=True)
Fictional data
Blinkit / Amazon Now figures in this chapter are fictional sample data for learning only. They do not show real company numbers. People names are for practice; e-mails use example.com.
Concepts in this chapter
- 23.1SettingWithCopy and Chained Assignment
- 23.2Wrong dtypes and Silent NaNs
- 23.3Merge Row Explosion (Many-to-Many)
- 23.4Timezone-Naive vs IST Mistakes
- 23.5Filters That Drop Too Much
- 23.6Debugging Checklist
- 23.7Practice, Tip and Close
The chapter recap is at the end of the last concept page.