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[Pandas] - pd.read_csv(), pd.head(), pd.tail(), pd.count()をマスターする

2022/01/22に公開
Python
pandas
tech

Pandas の基本コマンド - pd.read_csv(), pd.head(), pd.tail(), pd.count()をマスターする

  • read_csv(path)
import pandas as pd
import os

# pathの確認
path = '../src/titanic.csv'
os.path.exists(path)

True

pd.read_csv()

df = pd.read_csv(path)
len(df)

891

pd.head()

df.head()

<div>
<style scoped>
.dataframe tbody tr th:only-of-type {
vertical-align: middle;
}

.dataframe tbody tr th {
    vertical-align: top;
}

.dataframe thead th {
    text-align: right;
}

</style>
<table border="1" class="dataframe">
<thead>
<tr style="text-align: right;">
<th></th>
<th>PassengerId</th>
<th>Survived</th>
<th>Pclass</th>
<th>Name</th>
<th>Sex</th>
<th>Age</th>
<th>SibSp</th>
<th>Parch</th>
<th>Ticket</th>
<th>Fare</th>
<th>Cabin</th>
<th>Embarked</th>
</tr>
</thead>
<tbody>
<tr>
<th>0</th>
<td>1</td>
<td>0</td>
<td>3</td>
<td>Braund, Mr. Owen Harris</td>
<td>male</td>
<td>22.0</td>
<td>1</td>
<td>0</td>
<td>A/5 21171</td>
<td>7.2500</td>
<td>NaN</td>
<td>S</td>
</tr>
<tr>
<th>1</th>
<td>2</td>
<td>1</td>
<td>1</td>
<td>Cumings, Mrs. John Bradley (Florence Briggs Th...</td>
<td>female</td>
<td>38.0</td>
<td>1</td>
<td>0</td>
<td>PC 17599</td>
<td>71.2833</td>
<td>C85</td>
<td>C</td>
</tr>
<tr>
<th>2</th>
<td>3</td>
<td>1</td>
<td>3</td>
<td>Heikkinen, Miss. Laina</td>
<td>female</td>
<td>26.0</td>
<td>0</td>
<td>0</td>
<td>STON/O2. 3101282</td>
<td>7.9250</td>
<td>NaN</td>
<td>S</td>
</tr>
<tr>
<th>3</th>
<td>4</td>
<td>1</td>
<td>1</td>
<td>Futrelle, Mrs. Jacques Heath (Lily May Peel)</td>
<td>female</td>
<td>35.0</td>
<td>1</td>
<td>0</td>
<td>113803</td>
<td>53.1000</td>
<td>C123</td>
<td>S</td>
</tr>
<tr>
<th>4</th>
<td>5</td>
<td>0</td>
<td>3</td>
<td>Allen, Mr. William Henry</td>
<td>male</td>
<td>35.0</td>
<td>0</td>
<td>0</td>
<td>373450</td>
<td>8.0500</td>
<td>NaN</td>
<td>S</td>
</tr>
</tbody>
</table>
</div>

pd.tail()

df.tail()

<div>
<style scoped>
.dataframe tbody tr th:only-of-type {
vertical-align: middle;
}

.dataframe tbody tr th {
    vertical-align: top;
}

.dataframe thead th {
    text-align: right;
}

</style>
<table border="1" class="dataframe">
<thead>
<tr style="text-align: right;">
<th></th>
<th>PassengerId</th>
<th>Survived</th>
<th>Pclass</th>
<th>Name</th>
<th>Sex</th>
<th>Age</th>
<th>SibSp</th>
<th>Parch</th>
<th>Ticket</th>
<th>Fare</th>
<th>Cabin</th>
<th>Embarked</th>
</tr>
</thead>
<tbody>
<tr>
<th>886</th>
<td>887</td>
<td>0</td>
<td>2</td>
<td>Montvila, Rev. Juozas</td>
<td>male</td>
<td>27.0</td>
<td>0</td>
<td>0</td>
<td>211536</td>
<td>13.00</td>
<td>NaN</td>
<td>S</td>
</tr>
<tr>
<th>887</th>
<td>888</td>
<td>1</td>
<td>1</td>
<td>Graham, Miss. Margaret Edith</td>
<td>female</td>
<td>19.0</td>
<td>0</td>
<td>0</td>
<td>112053</td>
<td>30.00</td>
<td>B42</td>
<td>S</td>
</tr>
<tr>
<th>888</th>
<td>889</td>
<td>0</td>
<td>3</td>
<td>Johnston, Miss. Catherine Helen "Carrie"</td>
<td>female</td>
<td>NaN</td>
<td>1</td>
<td>2</td>
<td>W./C. 6607</td>
<td>23.45</td>
<td>NaN</td>
<td>S</td>
</tr>
<tr>
<th>889</th>
<td>890</td>
<td>1</td>
<td>1</td>
<td>Behr, Mr. Karl Howell</td>
<td>male</td>
<td>26.0</td>
<td>0</td>
<td>0</td>
<td>111369</td>
<td>30.00</td>
<td>C148</td>
<td>C</td>
</tr>
<tr>
<th>890</th>
<td>891</td>
<td>0</td>
<td>3</td>
<td>Dooley, Mr. Patrick</td>
<td>male</td>
<td>32.0</td>
<td>0</td>
<td>0</td>
<td>370376</td>
<td>7.75</td>
<td>NaN</td>
<td>Q</td>
</tr>
</tbody>
</table>
</div>

df.shape

(891, 12)

pd.count()

df.count()

PassengerId    891
Survived       891
Pclass         891
Name           891
Sex            891
Age            714
SibSp          891
Parch          891
Ticket         891
Fare           891
Cabin          204
Embarked       889
dtype: int64

まとめ

  • pd.read_csv()
  • pd.head()
  • pd.tail()
  • pd.count()

の使い方を学びました！

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