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I'm plotting some data imported from a csv file; a simple line graph works ok except that there are messy-looking lines where the data points connect (they're angled oddly and give the graph an overall cluttered look).

I want to change to a scatter-plot with lines between the points, hoping that this will remove the issue. However, when I plot a scatter-plot, the datetime from my csv is rejected and the following error message is displayed.

Does anyone have any ideas how I can use csv datetime with a scatter-plot. Or, even better, how I can stop those annoying messy lines in a line-graph? This latter would be the ideal option.

Error message for the .values solution...

My code is below:

import matplotlib.pyplot as plt 
import pandas as pd
import os
import matplotlib.dates as mdates 

# Read the file in csv 
File = pd.read_csv("Timeline.csv") 

# Where to save the output
outputDirectory = 'Z:\15_Hawaii\Plotting\'
if not os.path.exists(outputDirectory):
 os.makedirs(outputDirectory)

# Datetime selection
time = File.iloc[:,0] 
time_time = pd.to_datetime(time, format = '%m/%d/%Y')
time_time = pd.to_datetime(time_time, format = '%m/%d/%Y')
time_day = mdates.DayLocator()

# Kona data selection
Kona = File.iloc[:,2]

# defining the names which will be called
fig, host = plt.subplots()
ax = plt.gca()

# simple plot of the data
K_plot, = host.plot(time_time, Kona, color=[0,0.690196078,0.941176471], linewidth=1, label="Kona")

# attempt to scatter plot the data
K_plot, = plt.scatter(time_time, Kona, color=[0,0.690196078,0.941176471], linewidth=1, label="Kona")

# other plotting parameters
ax.xaxis.grid(linestyle='dotted')
plt.setp(ax.xaxis.get_majorticklabels(), rotation=80 )
fig.set_size_inches(12, 5)

plt.savefig(outputDirectory + 'SO2_PLOT_1' + '.png', bbox_inches='tight', dpi=300, pad_inches=0.0) 

It seems that, from the image, your imported dataframe's first row contains the strings 'Date', 'Time' and 'Kona_data'. If you read from the second row like this, then does the problem persist?

time = File.iloc[1:,0] 
Kona = File.iloc[1:,2]