Phyton: graph from csv filtered by pandas shows no graph-CodePudding

I would like to create a graph on filtered data from a csv. A graph is created but without content.

Here is the code and the result:

# var 4 graph
xs = []
ys = []

name = "Anna"
gender = "F"
state = "CA"


# 4 reading csv file
import pandas as pd

# reading csv file
dataFrame = pd.read_csv("../Kursmaterialien/data/names.csv")
#print("DataFrame...\n",dataFrame)

# select rows containing text 
dataFrame = dataFrame[(dataFrame['Name'] == name)&dataFrame['State'].str.contains(state)&dataFrame['Gender'].str.contains(gender)]
#print("\nFetching rows with text ...\n",dataFrame)

print(dataFrame)

# append var with value
xs.append(list(dataFrame['Year']))
ys.append(list(dataFrame['Count']))
#xs.append(list(map(str,dataFrame['Year'])))
#ys.append(list(map(str,dataFrame['Count'])))


print(xs)
print(ys)

Result from print(xs) and print(ys)

%matplotlib inline
import matplotlib.pyplot as plt
plt.plot(xs,ys)
plt.show()

Resulting plot

I see that the variables start with two brackets, but don't know if that is the problem and how to fix it.

The graphic should look something like this

CodePudding user response：

You are correct about the two brackets, you have to extract the data from the inner bracket. This is done by setting the indice to 0 to get the first column (which is also the only one).

This should work:

XS=xs[0]
YS=ys[0]
plt.plot(XS,YS)
plt.show()

With your double brackets, the plt.plot is plotting each pairs of points as a different element. And plotting a point doesn't draw a line, as by default the makers are off. If you try to add markers to your plot, you will see the markers in different colours, but no lines.

plt.plot(xs,ys,'o') #round marker