CODEWITHSUNDEEP
pythonpandas
Julian
Julian

Reputation: 441

How do I graph data that I got from SQL?

I'm doing an exercise in DataQuest where I'm trying to graph a set of data that I got from SQL.

It gives me the error:

AttributeError: 'str' object has no attribute 'values'

How do I have name on the x-axis and Pop_Density on the y-axis? I understand that Python can't graph the name but how do I reference the name along with the number? Do I have to transform the DataFrame into a dictionary first? The line with the problem is commented below.

import pandas as pd
import sqlite3

conn = sqlite3.connect("factbook.db")

q7 = '''
SELECT name, CAST(population as float)/CAST(area_land as float) AS Pop_Density
FROM facts
ORDER BY Pop_Density DESC
LIMIT 20
'''

density = pd.read_sql_query(q7, conn)
print(density)

Output Population Density

%matplotlib inline

import matplotlib.pyplot as plt
import seaborn as sns

fig = plt.figure(figsize=(10,10))
ax = fig.add_subplot(111)

bar_heights = density['name'].iloc[0].values # <-- line with problem. 
bar_positions = arange(5) + 0.75
tick_positions = range(1, 20)

ax.bar(bar_positions, bar_heights, 0.5)
ax.set_xticks(tick_positions)
ax.set_xticklabels(num_cols, rotation=90)

ax.set_xlabel("Country")
ax.set_ylabel("Population Density")
ax.set_title("Countries With The Highest Population Density")

Upvotes: 2

Views: 61

Answers (1)

caverac
caverac

Reputation: 1637

bar_heights = density['Pop_Density'].values
bar_positions = np.arange(len(bar_heights)) + 0.75
tick_positions = range(1, len(bar_heights) + 1)

ax.bar(bar_positions, bar_heights, 0.5)
ax.set_xticks(tick_positions)
ax.set_xticklabels(density['name'], rotation=90)

Upvotes: 2

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