[Python combat basics] How does Pandas parse a certain data from a string and count the data more than once

Table of contents

1. The actual combat scene

2. Main points of knowledge

file read and write

Basic grammar

Pandas

list

Three, rookie combat

1. Create a python file

2. Running results 

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1. The actual combat scene

Practical scenario: How does Pandas parse a certain data from a string and count the data more than once

2. Main points of knowledge

• file read and write

• Basic grammar

• Pandas

• list

Three, rookie combat

Schedule now!

1. Create a python file

import pandas as pd

df = pd.read_json('market.json')
# profile形如：^AEX (Holandia)
#遍历
df['country'] = df['profile'].map(  lambda x: x.split("(")[1].split(")")[0]
)
print(df.head(5))

df_counts = df["country"].value_counts()
print(df_counts)
print(list(df_counts[df_counts > 1].index))

2. Running results 

           profile time price change pct_change reference_price open low high country
0 ^ AEX (Netherlands) 14:12 548.73 7.95 (+ 1.47%) 540.78 546.55 544.72 550.72 Netherlands
1 ^ ATX (Austria) 14:11 2147.90 17.68 (+ 0.83%) 2130.22 2131.47 2118.71 2163.92 Austria
2 ^ ATXC (Greece) 14:13 621.82 -2.80 (-0.45%) 624.62 627.48 621.82 631.70 Greece
3 ^ BEL20 (Belgium) 14:11 3251.39 30.51 (+ 0.95%) 3220.88 3252.21 3228.77 3266.11 Belgium
4 ^ BUX (Hungary ) 14:12 32 831.01 534.27 (+ 1.65%) 32 296.74 32 421.05 32421.05 32 865.43 Hungary
Russia 2
Great Britain 2
Netherlands 1
Finland 1
Turkey 1
Switzerland 1
Czech Republic 1
Portugal 1
Norway 1
Sweden 1
Denmark 1
Austria 1
Spain 1
Italy 1
Germany 1
France 1
Hungary 1
Belgium 1
Greece 1
Poland 1
Name: country, dtype: int64
['Russia', 'United Kingdom' ]

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