64 lines
860 B
Markdown
64 lines
860 B
Markdown
---
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id: 5e9a093a74c4063ca6f7c15e
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title: Data Cleaning with DataFrames
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challengeType: 11
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isHidden: true
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videoId: sTMN_pdI6S0
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---
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## Description
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<section id='description'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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question:
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text: |
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What will the following code print out?:
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```py
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import pandas as pd
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import numpy as np
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s = pd.Series([np.nan, 1, 2, np.nan, 3])
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s = s.fillna(method='ffill')
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print(s)
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```
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answers:
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- |
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```
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0 1.0
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1 1.0
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2 2.0
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3 3.0
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4 3.0
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dtype: float64
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```
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- |
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```
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0 NaN
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1 1.0
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2 2.0
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3 2.0
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4 3.0
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dtype: float64
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```
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- |
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```
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0 NaN
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1 1.0
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2 2.0
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3 NaN
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4 3.0
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dtype: float64
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```
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solution: 2
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```
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</section>
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