Learning Pandas (11)

Original English: 11-lesson

Reads data from multiple Excel files and merges the data together in a dataframe.

Import pandas as PD
import matplotlib
import OS
import sys
%matplotlib inline

Print (' Python version ' + sys.version)
print (' Pandas version ' + pd.__version__)
print (' matplotlib version ' + Mat PLOTLIB.__VERSION__)

Python version 3.6.1 | Packaged by Conda-forge | (Default, Mar 2017, 21:57:00) 
[GCC 4.2.1 compatible Apple LLVM 6.1.0 (clang-602.0.53)]
Pandas version 0.19.2
matplotlib version 2.0.2

Create 3 Excel files

# Create Dataframe
d = {' Channel ': [1], ' number ': [255]}
df = pd. Dataframe (d)
DF

Number

	Channel
0	1	255

# Export to Excel file

df.to_excel (' test1.xlsx ', sheet_name = ' test1 ', index = False)
df.to_excel (' test2.xlsx ', sheet_ name = ' Test2 ', index = false)
df.to_excel (' test3.xlsx ', sheet_name = ' test3 ', index = false)
print (' Done ')

    Done

Read 3 Excel file data into a dataframe

Read the Excel file name into a list and make sure that there are no other Excel files in the directory.

# Place the name of the list
FileNames = []

# Your path to the Excel file may be different and needs to be modified.
Os.chdir (r "./")

# Find all file name extensions are. xlsx files for file in
os.listdir ("."):
    if Files.endswith (". xlsx"):
        filenames.append (Files)

FileNames

    [' test1.xlsx ', ' test2.xlsx ', ' test3.xlsx ']

Create a function to process all the Excel files.

def GetFile (Fnombre):

    # Path of Excel file
    # Your path to the Excel file may be different and needs to be modified.
    location = R './' + fnombre

    # Read data in Excel file
    # 0 = first tab
    DF = pd.read_excel (location, 0)

    # mark the data from which text The
    df[' file ' = Fnombre

    # takes the ' file ' column as the index return
    df.set_index ([' File '])

Create a dataframe for each file, and put all the dataframe in a list.

That
Df_list = [DF, DF, DF]

# Create a dataframe list
df_list = [GetFile (fname) for fname in FileNames]
df_list

[            Channel  number
 file                       
 test1.xlsx        1     255,             Channel  number
 file                       
 TEST2.XLSX        1     255,             Channel  number
 File                       
 test3.xlsx        1     255]

# Merge all the dataframe in the list into a
BIG_DF = Pd.concat (df_list)
BIG_DF

Number

	Channel
File
Test1.xlsx	1	255
Test2.xlsx	1	255
Test3.xlsx	1	255

Big_df.dtypes

    Channel    Int64
    number     Int64
    dtype:object

# Draw a picture
big_df[' Channel '].plot.bar ();