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I am trying to perform some analysis on data. I got csv file and I convert it into pandas dataframe. the data looks like this. Its has several columns, but I am trying to draw x-axis as date column. .

the pandas dataframe looks like this 

print (df.head(10)

    cus-id        date       value_limit
0   10173         2011-06-12        455
1   95062         2011-09-11        455
2   171081        2011-07-05        212
3   122867        2011-08-18        123
4   107186        2011-11-23        334
5   171085        2011-09-02        376
6   169767        2011-07-03        34
7   80170         2011-03-23        34
8   154178        2011-10-02        34
9   3494          2011-01-01        34

I am trying to plot date data because there are multiple values for same date. for this purpose I am trying to plot x-asis ticks as date. since the minimum date in date column is 2011-01-01 and maximum date is 2012-04-20.

I tried something like this

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import datetime
import matplotlib.dates as mdates

df = pd.read_csv('rio_data.csv', delimiter=',')
print (df.head(10))
d = []
for dat in df.date:
    # print (dat)
    d.append(datetime.strptime(df['date'], '%Y-%m-%d'))
days = dates.DayLocator()
datemin = datetime(2011, 1, 1)
datemax = datetime(2012, 4, 20) 
fig = plt.figure()
ax = fig.add_subplot(111)
ax.xaxis.set_major_locator(days)
ax.set_xlim(datemin, datemax)
ax.set_ylabel('Count values')

But I am getting this error. 

 AttributeError: 'DataFrame' object has no attribute 'date'

I am trying to draw date as x-axis, it should look like this. enter image description here

Can someone help me to draw the x-axis as date column. I would be grateful.

Trenton McKinney
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Rio
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  • You have to set the data frame index to the date time column. See this link: https://stackoverflow.com/questions/40815238/python-pandas-convert-index-to-datetime – Dodge Mar 21 '18 at 23:41
  • @W.Dodge I will give it a try. thanks a lot – Rio Mar 21 '18 at 23:50
  • @W.Dodge I set date column as index, but there are too many values that the x-axis looks like a dark line. I add the graph below – Rio Mar 22 '18 at 00:00
  • you can run the text perpendicular to x axes for crowded axes. You can also set figure size to give more space. I'm writing an answer that may help. – Dodge Mar 22 '18 at 00:02
  • @W.Dodge Thanks a lot for the help – Rio Mar 22 '18 at 00:03

2 Answers2

8

Set the index as a datetime dtype

If you set the index to the datetime series by converting the dates with pd.to_datetime(...), matplotlib will handle the x axis for you.

Here is a minimal example of how you might deal with this visualization.

Plot directly with pandas.DataFrame.plot, which uses matplotlib as the default backend.

Simple example:

import pandas as pd
import matplotlib.pyplot as plt

date_time = ["2011-09-01", "2011-08-01", "2011-07-01", "2011-06-01", "2011-05-01"]

# convert the list of strings to a datetime and .date will remove the time component
date_time = pd.to_datetime(date_time).date
temp = [2, 4, 6, 4, 6]

DF = pd.DataFrame({'temp': temp}, index=date_time)

ax = DF.plot(x_compat=True, rot=90, figsize=(6, 5))

This will yield a plot that looks like the following:

enter image description here

Setting the index makes things easier

The important note is that setting the DataFrame index to the datetime series allows matplotlib to deal with x axis on time series data without much help.

Follow this link for detailed explanation on spacing axis ticks (specifically dates)

Trenton McKinney
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Dodge
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3

You missed a ' line 12. It cause the SyntaxError.

This should correct the error.

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import datetime
import matplotlib.dates as mdates

df = pd.read_csv('rio_data.csv', delimiter=',')
print (df.head(10))
d = []
for dat in df.date:
    # print (dat)
    d.append(datetime.strptime(df['date'], '%Y-%m-%d'))
days = dates.DayLocator()
datemin = datetime(2011, 1, 1)
datemax = datetime(2012, 4, 20) 
fig = plt.figure()
ax = fig.add_subplot(111)
ax.xaxis.set_major_locator(days)
ax.set_xlim(datemin, datemax)
ax.set_ylabel('Count values')
AdriBento
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  • Whilst this is the reason, you shouldn’t answer typo questions. They should instead be closed and perhaps add a comment – DavidG Mar 21 '18 at 23:43
  • @A.Ben thanks i realize that silly error, but still I am getting error. AttributeError: 'DataFrame' object has no attribute 'date' . should I update this error in my question? – Rio Mar 21 '18 at 23:46
  • Yes update it, We will try to resolve this problem instead of the typo one – AdriBento Mar 21 '18 at 23:47