import sys
print("Python version")
print (sys.version)

currency_1 = {'Pound': 0.091, 'Euro': 0.093, 'Usd': 0.121}
currency_2 = {'Pound': 0.083, 'Afghani': 9.12, 'Romanian_Leu': 2.08}

# for Python 3.5 or greater
# new dictionary is a shallowly merged dictionary of currency_1 and currency_2
# with values from currency_2 replacing those from currency_1
currency = {**currency_1, **currency_2 }
print(currency)

# in Python 2, (or 3.4 or lower) 
def merge_two_dicts(currency_1, currency_2):
    currency = currency_1.copy()   # start with currency_1
    currency.update(currency_2)    # modifies currency with currency_2
    return currency

currency = merge_two_dicts(currency_1, currency_2)
print(currency)

# Python 3.9.0 or greater
currency = currency_1 | currency_2
print(currency)

# output
# Python version
# 3.9.0 (v3.9.0:9cf6752276, Oct  5 2020, 11:29:23) 
# [Clang 6.0 (clang-600.0.57)]
# {'Pound': 0.083, 'Euro': 0.093, 'Usd': 0.121, 'Afghani': 9.12, 'Romanian_Leu': 2.08}
# {'Pound': 0.083, 'Euro': 0.093, 'Usd': 0.121, 'Afghani': 9.12, 'Romanian_Leu': 2.08}
# {'Pound': 0.083, 'Euro': 0.093, 'Usd': 0.121, 'Afghani': 9.12, 'Romanian_Leu': 2.08}